Federal Register, Volume 59 Issue 140 (Friday, July 22, 1994)

[Federal Register Volume 59, Number 140 (Friday, July 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17798]

[[Page Unknown]]

[Federal Register: July 22, 1994]

_______________________________________________________________________

Part V

Department of Transportation

_______________________________________________________________________

Federal Aviation Administration

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14 CFR Parts 23 and 91

Airworthiness Standards; Systems and Equipment Proposals Based on
European Joint Aviation Requirements Proposals; Proposed Rule
DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 23 and 91

[Docket No. 27806; Notice No. 94-21]
RIN: 2120-AE59

Airworthiness Standards; Systems and Equipment Proposals Based on
European Joint Aviation Requirements Proposals

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes changes to the systems and equipment
airworthiness standards for normal, utility, acrobatic, and commuter
category airplanes. These proposals arise from the joint effort of the
Federal Aviation Administration (FAA) and the European Joint Aviation
Authorities (JAA) to harmonize the Federal Aviation Regulations (FAR)
and the Joint Aviation Requirements (JAR) for airplanes that will be
certificated in these categories. The proposed changes would provide
nearly uniform systems and equipment airworthiness standards for
airplanes certificated in the United States under 14 CFR part 23 (part
23) and in the JAA countries under Joint Aviation Requirements 23 (JAR
23), thereby simplifying airworthiness approval for import and export
purposes.

DATES: Comments must be submitted on or before November 21, 1994.

ADDRESSES: Comments on this document should be mailed in triplicate to:
Federal Aviation Administration, Office of the Chief Counsel,
Attention: Rules Docket (AGC-200), Docket No. 27806, 800 Independence
Avenue SW., Washington, DC 20591.
Comments delivered must be marked Docket No. 27806. Comments may be
inspected in Room 915G weekdays between 8:30 a.m. and 5 p.m., except on
Federal holidays.
In addition, the FAA is maintaining an information docket of
comments in the Office of the Assistant Chief Counsel, ACE-7, Federal
Aviation Administration, Central Region, 601 East 12th Street, Kansas
City, Missouri 64106. Comments in the duplicate information docket may
be inspected in the Office of the Assistant Chief Counsel weekdays,
except Federal holidays, between the hours of 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Earsa Tankesley, ACE-112, Small
Airplane Directorate, Aircraft Certification Service, Federal Aviation
Administration, 601 East 12th Street, Kansas City, Missouri 64106;
telephone (816) 426-5688.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Comments relating to the environmental, energy, or
economic impact that might result from adopting the proposals in this
notice are also invited. Substantive comments should be accompanied by
cost estimates. Comments should identify the regulatory docket or
notice number and should be submitted in triplicate to the Rules Docket
address specified above. All comments received on or before the
specified closing date for comments will be considered by the
Administrator before taking action on this proposed rulemaking. The
proposals contained in this notice may be changed in light of comments
received. All comments received will be available, both before and
after the closing date for comments, in the Rules Docket for
examination by interested persons. A report summarizing each FAA-public
contact concerned with the substance of this proposal will be filed in
the docket. Commenters wishing the FAA to acknowledge receipt of their
comments submitted in response to this notice must include a
preaddressed, stamped postcard on which the following statement is
made: ``Comments to Docket No. 27806.'' The postcard will be date
stamped and returned to the commenter.

Availability of NPRM

Any person may obtain a copy of this NPRM by submitting a request
to the Federal Aviation Administration, Office of Public Affairs,
Attention: Public Inquiry Center, APA-200, 800 Independence Avenue,
SW., Washington, DC 20591, or by calling (202) 267-3484. Communications
must identify the notice number of this NPRM.
Persons interested in being placed on the mailing list for future
NPRM's should request, from the above office, a copy of Advisory
Circular No. 11-2A, Notice of Proposed Rulemaking Distribution System,
which describes the application procedure.

Background

At the June 1990 meeting of the JAA Council (consisting of JAA
members from European countries) and the FAA, the FAA Administrator
committed the FAA to support the harmonization of the FAR with the JAR
being developed for use by the European authorities who are members of
the JAA. In response to this commitment, the FAA Small Airplane
Directorate established an FAA Harmonization Task Force to work with
the JAR 23 Study Group to harmonize part 23 and the proposed JAR 23.
The General Aviation Manufacturers Association (GAMA) also established
a JAR 23/part 23 Committee to provide technical assistance in this
effort.
Following a review of the first draft of proposed JAR 23, members
of the FAA Harmonization Task Force and the GAMA Committee met in
Brussels, Belgium for the October 1990 meeting of the JAR 23 Study
Group. Representatives from the Association Europeene des
Constructeures de Material Aerospatial (AECMA), an organization of
European airframe manufacturers, also attended. The main agenda item
for this meeting was the establishment of procedures to accomplish
harmonization of the airworthiness standards for normal, utility, and
acrobatic category airplanes. The JAA had decided that its initial
rulemaking effort should be limited to these three categories and that
commuter category airworthiness standards should be addressed
separately.
After that meeting, technical representatives from each of the four
organizations (GAMA, AECMA, FAA and JAA) met to resolve differences
between the proposed JAR and part 23. This portion of the harmonization
effort involved a number of separate meetings of specialists in the
flight, airframe, powerplant, and systems disciplines. These meetings
showed that harmonization would require revisions to both part 23 and
the proposed JAR 23.
Near the end of the effort to harmonize the normal, utility, and
acrobatic category airplane airworthiness standards, the JAA requested
and received recommendations from its member countries on proposed
airworthiness standards for commuter category airplanes. The JAA and
the FAA held specialist and study group meetings to discuss these
recommendations, which resulted in proposals to revise portions of the
part 23 commuter category airworthiness standards.
Unlike the European rules, where commuter category airworthiness
standards are separate, for U.S. rulemaking, it is advantageous to
adopt normal, utility, acrobatic, and commuter category airworthiness
standards simultaneously, since commuter category airworthiness
standards are already contained in part 23. Accordingly, this NPRM
proposes to revise the systems and equipment airworthiness standards
for all part 23 airplanes.
During the part 23 harmonization effort, the FAA established an
Aviation Rulemaking Advisory Committee (ARAC) (56 FR 2190, January 22,
1991), which held its first meeting on May 23, 1991. The ARAC on
General Aviation and Business Airplane (GABA) Issues was established at
that meeting to provide advice and recommendations to the Director,
Aircraft Certification Service, FAA, regarding the airworthiness
standards in part 23 as well as related provisions of parts 91 and 135
of the regulations.
The FAA announced, on June 2-5, 1992, at the JAA/FAA Harmonization
Conference in Toronto, Ontario, Canada, that it would consolidate
within the ARAC structure an ongoing objective to ``harmonize'' the JAR
and the FAR. Coinciding with that announcement, the FAA assigned the
ARAC on GABA Issues those rulemaking projects related to JAR/part 23
harmonization that were in final coordination between the JAA and the
FAA. The harmonization process included the intention to present the
results of JAA/FAA coordination to the public as NPRM's. Subsequently,
the ARAC on GABA Issues established an ARAC-JAR 23 Study Group.
The JAR 23 Study Group made recommendations to the ARAC on GABA
Issues concerning the FAA disposition of the rulemaking issues
coordinated between the JAA and the FAA. The draft NPRMs previously
prepared by the FAA harmonization team were made available to the
harmonization working group to assist them in their effort.
A notice of the formation of the JAR 23 Harmonization Working Group
was published on November 30, 1992 (57 FR 56626). The group held its
first meeting on February 2, 1993. These efforts resulted in the
proposals for systems and equipment airworthiness standards contained
in this notice. The ARAC on GABA Issues agreed with these proposals.
The FAA received unsolicited comments from the JAA dated January
20, 1994, concerning issues that were left unresolved with the JAR 23
Study Group. The JAR/FAR 23 Harmonization Working Group did not address
some of the unresolved issues because the JAA had not yet reached
positions on those issues. Unresolved issues will be dealt with at
future FAR/JAR Harmonization meetings. With respect to other issues
unresolved by the JAR 23 Study Group, the JAR/FAR 23 Harmonization
Working Group recommendations did not reflect harmonization, but
reflected the technical discussion of the merits of each issue that had
been thoroughly debated at the JAR/FAR 23 Harmonization meetings. (The
Working Group Chairperson had been present at the Harmonization
meetings.) The JAA comments have been placed in the docket for this
proposal, and will be considered along with those received during the
comment period.
Following completion of these harmonization efforts, the FAA
determined that the proposed revisions to part 23 were too numerous for
a single NPRM. The FAA decided to simplify the issues by issuing four
NPRM's. These NPRM's address the airworthiness standards in the
specific areas of systems and equipment, powerplant, flight, and
airframe. These NPRM's propose changes in all seven subparts of part
23. Since there is some overlap, interested persons are advised to
review all four NPRM's to identify all proposed changes to a particular
section.

Discussion of Proposals

Section 23.677 Trim Systems

Proposed revised Sec. 23.677(a) would clarify the need to mark the
lateral and directional trim indicators with the neutral trim position.
Since trim indicators on most airplanes are currently marked with the
neutral position of the trimming device, this proposal would
standardize the cockpit markings for all airplanes.
Revised paragraph (a) would also add a requirement for the pitch
trim indicator to be marked with the proper pitch trim range for the
takeoff of the airplane. Some takeoff accidents, including some
involving fatalities, have occurred because the pitch trim was not set
to the proper range needed for the airplane takeoff. Because of this
accident experience, most of the current airplane manufacturers mark
the pitch trim indicator with the pitch trim range for takeoff.
Therefore, the proposed marking requirement would not have a
significant impact on future airplane designs and would ensure that the
markings needed for a safe takeoff are provided for the pilots' use.

Section 23.691 Artificial Stall Barrier System

This proposed new section would provide standards for stall barrier
systems if a stall barrier is necessary to show compliance with
Sec. 23.201(c).
The requirements of Sec. 23.201(c) provide criteria for the in-
flight demonstration of wings level stall. The requirements also
specify the means of identifying when a stall has occurred. Amendment
No. 23-45 (58 FR 42136, August 6, 1993) revised Sec. 23.201(c) by
adding the activation of an artificial stall barrier as an acceptable
means of identifying when a stall has occurred.
As the technology of airplane designs improved and engines with
increased power became available, airplanes were developed that did not
meet the older wings level stall requirement of Sec. 23.201.
Consequently, these airplanes were equipped with an artificial stall
barrier that moved the airplane elevator controls and caused a nose
down pitching motion similar to the pitching motion of airplanes that
meet the wings level stall requirement of Sec. 23.201. The manufacturer
selected the airspeed where this pitching motion occurred and flight
testing established compliance with the other flight regulations at
airspeeds above the speed selected for the push. These stall barrier
systems are commonly called ``stick pushers.'' Such systems have been
accepted for compliance with Sec. 23.201 under the equivalent safety
provisions of Sec. 21.21(b)(1), since they provide a pitch motion that
is equivalent to that experienced during stalls of airplanes that meet
the stall requirements of Sec. 23.201. Appropriate compliance with
other applicable requirements of part 23 has been established by other
design characteristics of the stall barrier system.
The provisions of the proposed new section are based on system
design characteristics necessary to ensure the safe operation of
previously approved stall barrier systems. The proposed section also
requires such systems to include provisions to prevent unwanted
activation of the stall barrier systems. This is necessary to ensure
that such systems do not cause downward pitching motions at higher
airspeeds when such pitching could be unsafe.
The proposed sections would basically codify those provisions that
have been found necessary for approving stick pusher systems under the
equivalent safety requirements of Sec. 21.21(b)(1). Therefore, in
effect, no new requirements would be added by this proposed amendment.
The proposed new section would be applicable only to airplanes with
flight characteristics that need an artificial stall barrier system to
ensure safe operation of that airplane. Including provision for the
installation of an optional stick pusher system would relieve the
manufacturer of the financial burden that would be needed to redesign
the airplane so that it would meet the wings level stall requirements.

Section 23.697 Wing Flap Controls

Proposed new Sec. 23.697(c) would provide safety standards for the
wing flap control lever designs installed in airplanes that use wing
flap settings other than fully retracted when showing compliance with
Sec. 23.145. This revision is needed to ensure that the flap settings,
which establish the safe operation of the airplane, can be positively
selected.

Section 23.701 Flap Interconnection

Section 23.701 (a)(1) and (a)(2) would be revised to clarify the
requirements for flap systems installed on part 23 airplanes. Following
the revision of Sec. 23.701, as adopted by Amendment No. 23-42 (56 FR
353, January 3, 1991), the FAA discovered that the new requirements
could be interpreted in a way that was not intended and that this
interpretation could result in approval of airplanes with unsafe flight
characteristics in the event of flap failure. To clarify the intent of
the requirements, the FAA issued on March 14, 1991, a policy letter to
all aircraft certification offices that provided guidance for the
correct application of the requirements.
Since then, the FAA has reexamined the requirements and determined
that Sec. 23.701 (a)(1) and (a)(2) need to be revised to ensure that a
failure of the flap system would not create an asymmetric flap
configuration that could result in an unsafe flight condition.
Therefore, Sec. 23.701 (a)(1) and (a)(2) would be revised to clarify
that one of the following would apply:
(1) The moveable flap surfaces must be synchronized by a mechanical
interconnection or by an approved equivalent means, that is independent
of the flap drive system.
(2) The wing flap system must be designed so that any failures of
the flap system that would result in an unsafe flight characteristic of
the airplane, such as flap asymmetry, is extremely improbable.
These revisions would ensure that a failure of the flap drive
systems will not result in a flap asymmetry configuration.

Section 23.703 Takeoff Warning System

This proposed new section would require a takeoff warning system on
some commuter category airplanes. The requirement would be applicable
if the flight evaluation showed that an unsafe takeoff condition would
result if lift devices or longitudinal trim devices are set to any
position outside the approved takeoff range. If the evaluation shows
that no unsafe condition would result at any setting of these devices,
a takeoff warning system would not be required. For those airplanes on
which a warning system must be installed, the proposal would provide
requirements for the installation of the system.

Section 23.723 Shock Absorption Tests

Paragraph (b) of this section would be revised by changing the word
``reserved'' in the phrase ``reserved energy absorption capacity'' to
``reserve.''

Section 23.729 Landing Gear Extension and Retraction System

This proposal would revise Sec. 23.729(e) to clarify that a landing
gear indicator is required for each gear. The last sentence of current
Sec. 23.729(e) would also be removed. This sentence, which states that
the switches may be located where they are operated by the actual
landing gear locking latch or device, is advisory material and should
not be included in the requirements. If future guidance is needed to
identify acceptable switch locations, Advisory Circular 23.701-1 will
be revised to include that information.
This proposal would also add a new Sec. 23.729(g) requiring that if
the landing gear bay is used as the location for equipment other than
landing gear, the equipment must be designed and installed to minimize
damage. On larger airplanes, such as the commuter category, a primary
cause of damage to such equipment would be tire burst. In addition,
service history has shown that rocks, water, and slush enter the
landing gear bay and cause damage. The equipment on any size airplane
should be protected from damage by such external sources.

Section 23.735 Brakes

Section 23.735(a) would be revised to state plainly that wheel
brakes must be provided. A proposed new Sec. 23.735(c) would require
the brake system to be designed so that the brake manufacturer's
specified brake pressures are not exceeded during the landing distance
determination required by Sec. 23.75.
Proposed new Sec. 23.735(e), applicable to commuter category
airplanes, would require establishing the minimum rejected takeoff
brake kinetic energy capacity rating of each main wheel brake assembly.
Section 23.45 provides that the determination of the accelerate-stop
distance for commuter category airplanes be made in accordance with the
applicant's procedures for operation in service. The proposed
requirement is needed to ensure that the brakes will perform safely
under accelerate-stop conditions.

Section 23.745 Nose/Tail Wheel Steering

Proposed new Sec. 23.745 would provide requirements that apply if
nose/tail-wheel steering is installed. Advanced airplane design
technology, along with the need to safely control the airplane when it
is being operated on increasingly congested airports, has resulted in
several small airplanes being equipped with systems for ground steering
only.
The proposed new section would not require the installation of a
system for ground steering, but it would add requirements to define how
such a system should function if one is installed. It would also
require the steering system to be designed so that it will not
interfere with any installed landing gear retraction and extension
system.

Section 23.775 Windshields and Windows

Section 23.775(a) would be revised to state that internal glass
panels of windshields and windows must be constructed of a
nonsplintering material, such as nonsplintering glass. Currently
Sec. 23.775(a) requires nonsplintering safety glass only. A
nonsplintering material must be used to protect pilots from injury.
While nonsplintering glass is an acceptable standard, other
nonsplintering materials would be allowed under the proposal.
Section 23.775(c) would be revised to clarify that it applies to
pressurized airplanes if certification for operation up to and
including 25,000 feet is requested. This would not be a substantive
change. It has always applied to such airplanes but is not as directly
stated in the current rule as it would be in the proposed rule. Current
Sec. 23.775(e), which is being redesignated as Sec. 23.775(d) by this
notice without change, provides requirements for airplanes that are
certified for operations above 25,000 feet. This revision of paragraph
(c) and redesignation of paragraph (e) will clarify the requirements
that are applicable to airplanes approved for operations at different
altitudes. Redesignated paragraph (e) is revised to remove the
masculine gender by rephrasing ``when he is seated'' to read ``when the
pilot is seated.''
Section 23.775(h), introductory text, and paragraph (h)(1) would be
added to require windshield panes of commuter category airplanes that
are directly in front of the pilots to withstand the impact of a two
pound bird. This requirement is based on a Joint Aviation Authority
recommendation to add windshield bird strike protection for commuter
category airplanes. Following receipt of the recommendations, the FAA
obtained and reviewed the International Civil Aviation Organization
(ICAO) data on bird strikes that occurred on airplanes of 19,000 pounds
or less from 1981 through 1989. These data show that approximately 550
strikes occurred and that one out of seven strikes hit the windshield.
The bird strike reports, which include information on the type of bird,
the airplane altitude and/or airspeed, show the following:
1. More than one-half of the strikes (51.8 percent) occurred
between the ground and 100 feet above the ground.
2. Another one-fourth of the strikes (26.7 percent) occurred
between 101 and 1000 feet.
3. The airplane airspeed at the time of most of the strikes (85
percent) was 150 knots or less.
4. Where bird types were reported, 27.6 percent involved small
birds and 58.6 involved medium size birds.
5. Incidents where the airplane was damaged showed that 16.9
percent resulted from small bird strikes and 64 percent resulted from
strikes involving medium size birds.
Evaluation of these data indicate that most bird strikes occur at
takeoff and landing altitudes and airspeeds, and that medium or small
birds, many weighing two pounds or less, are most often struck.
Although only a few fatalities and injuries have resulted from these
reported bird strikes, the data indicates a high probability of bird
strikes during landings and takeoffs and the potential hazards of such
strikes.
This proposed new paragraph would require that the windshield panes
directly in front of the pilots of commuter category airplanes, and the
supportive structure for these panes, must withstand the impact of a
two-pound bird at an airplane's maximum approach flap speed.
Proposed Sec. 23.775(h)(2) would require the panels of the
windshield to be arranged so that, if one is damaged, other panels will
remain that will provide visibility for continuous safe flight and
landing of the airplane.
By requiring full protection against the strike of a two-pound bird
at approach speeds, some protection will also be provided if the
airplane strikes a larger bird or strikes a bird at a higher speed.

Section 23.783 Doors

Current Sec. 23.783(b) requires that passenger doors not be located
with respect to any propeller disk so as to endanger persons using the
door. Proposed paragraph (b) would add that passenger doors must be
located in relation to any other potential hazard that could endanger
persons using the door. The propeller disk remains the prominent hazard
but other items, such as hot deicer surfaces or sharp objects on the
airplane structure, are also hazards.
Proposed new paragraph (g) would require lavatory doors, if
installed, that would not trap occupants inside a closed and locked
lavatory compartment.

Section 23.785 Seats, Berths, Litters, Safety Belts, and Shoulder
Harnesses

Seat requirements of part 23 would be clarified by moving the seat
provisions in current Sec. 23.1307(a), which require a seat or berth
for each occupant, to the introductory text of Sec. 23.785. The
requirement of Sec. 23.1413, for a metal to metal latching device for
seat belts and shoulder harnesses would also be referenced in
Sec. 23.785(b). These proposed changes would combine related seat
requirements in one section.

Section 23.787 Baggage and Cargo Compartments

Section 23.787 would be revised by extending the present
requirements for cargo compartments to baggage compartments. As
proposed, future baggage compartments on all airplane categories would
be required to: Be placarded for their maximum weight capacity; have a
means to prevent the baggage from shifting; and have a means to protect
controls, wiring, lines, and equipment or accessories that are located
in the compartment and whose damage or failure would affect safe
operation of the airplane. These standards have been applicable to
cargo compartment designs for some time and should be applied to
baggage compartments since the same safety factors are involved.
Because manufacturers recognize the need for these standards, many of
these provisions have been included in the current design of baggage
compartments and, therefore, the proposed requirements are not expected
to create a significant burden. With this revision the commuter
category requirements of Sec. 23.787(g) would be redundant and that
requirement is being removed.
Proposed revisions to this section would also move the substance of
paragraphs (d) and (f) to a proposed new Sec. 23.855, which will
address cargo and baggage compartment fire protection.
Proposed new paragraph (c) of this section would require flight
crew emergency exits on all cargo configured airplanes to meet the
requirements of Sec. 23.807. This requirement would provide increased
assurance that flight crews of all cargo airplanes will have ready
access to an emergency exit.

Section 23.791 Passenger Information Signs

This proposed new section would require at least one illuminated
sign notifying all passengers when seat belts should be fastened. This
proposed requirement applies to airplanes where flightcrew members
cannot observe occupant seats or where the flightcrew member
compartment is separated from the passenger compartment. When
illuminated, the signs must be legible to all persons seated in the
passenger compartment. Each sign must be installed so that a flightcrew
member can turn it on and off from his or her station.

Section 23.807 Emergency Exits

Proposed new Sec. 23.807(a)(4) would provide the same protection
from any propeller disk and other potential hazard for a person who
uses emergency exits as that provided by proposed Sec. 23.783(b) for a
person who uses a passenger door. (See discussion for proposed
Sec. 23.783 in this notice.)
The proposed revision of Sec. 23.807(b) would provide that the
inside handles of emergency exits that open outward must be protected
against inadvertent operation. Currently this protection is required by
applying the general safety provisions of this subchapter. The addition
of the specific requirement in Sec. 23.807(b) would clarify the need
for this protection by providing a requirement that addresses outward
opening emergency exits.
The proposed revision to Sec. 23.807(b)(5) and new
Sec. 23.807(b)(6) would apply to acrobatic and utility category
airplanes that are approved for maneuvers, such a spinning. The
proposed rule would require that emergency exits for these category
airplanes allow the occupants to abandon the airplane at certain speeds
related to such maneuvers. These emergency exits need to function under
different environmental conditions than the emergency exits on normal
category airplanes. The revision of the text in paragraph (b)(5) would
provide the same terminology that is used in added new paragraph
(b)(6).

Section 23.841 Pressurized Cabins

Section 23.853 Passengers and Crew Compartment Interiors

This proposal would revise the section heading from ``Compartment
Interiors'' to ``Passenger and crew compartment interiors'' for
consistency with the introductory text of the section and to clarify
the content of the section.

Section 23.855 Cargo and Baggage Compartment Fire Protection

This proposed new section would require the following:
Proposed paragraph (a) would require all sources of heat within
each cargo and baggage compartment that are capable of igniting the
compartment contents to be shielded and insulated to prevent such
ignition.
Proposed paragraph (b) would require cargo and baggage compartments
to be constructed of materials that meet the appropriate provisions of
Sec. 23.853(d)(3). Currently these requirements apply to commuter
category airplanes and to the materials used in the compartments of
these airplanes. The proposed new requirement would expand this
applicability to the cargo and baggage compartments of all part 23
airplanes. In effect, the proposed new requirement would require
materials that are self-extinguishing rather than flame resistant as
currently required under Sec. 23.787(d).
Proposed new paragraph (c) would add new fire protection
requirements for cargo and baggage compartments for commuter category
airplanes. The proposed rule would require on of the following
alternatives: (1) Either the compartment must be located where pilots
seated at their duty station would easily discover the fire or the
compartment must be equipped with a smoke or fire detector system to
warn the pilot's station. The compartment must also provide access to
the compartment with a fire extinguisher. (2) The compartment may be
inaccessible, but must be equipped with a fire detector system that
warns the pilot station, and the compartment must have ceiling and
sidewall floor panels constructed of materials that have been subjected
to and meet the vertical self-extinguishing tests of appendix F of this
part. (3) The compartment must be constructed and sealed to contain any
fire.
The proposed new section is necessary for several reasons. The
proposals for additional requirements for commuter category airplane
cargo and baggage compartments were developed after an examination of
reported incidents of inflight fires and their causes. Although most of
these incidents of inflight fires occurred on transport category
airplanes, the reported sources of the fires showed that the fires
originate from sources, such as matches in the pockets of clothing,
that are as likely to be found on part 23 airplanes as on transport
category airplanes. The same potential for inflight fires exists on
commuter category airplanes and adequate protection should be provided.
The potential for inflight fires also showed a need to examine the
flame resistant requirements of current Sec. 23.787(d) and to consider
requirements that would improve the fire protection on other categories
of airplanes. As a part of this consideration, fire protection was
discussed with certain airframe manufacturing representatives.
Information provided in these discussions showed that materials that
meet self-extinguishing flame requirements are available at about the
same cost as materials that meet flame resistance requirements. Based
on a review of the fire incidents and the information on availability
of improved materials, the proposal for Sec. 23.855(b), which would
replace current Sec. 23.787(d), would require self-extinguishing
materials to be used in the cargo and baggage compartments of all part
23 airplanes.

Section 23.867 Electrical Bonding and Protection Against Lightning and
Static Electricity

This proposed revision would change the heading that precedes the
section from ``Lightning Evaluation'' to ``Electrical Bonding and
Lightning Protection.'' It would also revise the section heading from
``Lightning protection of structures'' to ``Electrical bonding and
protection against lightning and static electricity.'' The proposed
revisions more accurately clarify the content of the section.

Section 23.1303 Flight and Navigation Instruments

The lead in for Sec. 23.1303(a) would be revised to clarify that
the instruments required by this section are the minimum ones required.
Also, Sec. 23.1303(d) would add a requirement for those airplanes whose
performance must be based on weight, altitude, and temperature to be
equipped with a free air temperature indicator. A new sentence added to
Sec. 23.1303(e)(2) would state that nuisance overspeed warnings should
not occur at lower speeds where pilots might ignore the warning. A new
paragraph (f) would propose requirements for attitude instruments that
include a means for flightcrew members to adjust the reference symbol.
Finally, it would add a new paragraph (g) to define certain specific
instruments required for a commuter category airplane.
The proposal for Sec. 23.1303(e)(2) was developed following a Joint
Aviation Authority recommendation that the warning should not occur
below the maximum operating limit speed (VMO/MMO)/ To
determine the effect that this recommended VMO/MMO limit
would have on the design of overspeed warning devices, the FAA
contacted several equipment manufacturers. These manufacturers
responded that it would be possible to establish a lower limit at
VMO/MMO, but that the design changes needed to ensure that
the warning occurred between the presently required upper limit and the
recommended lower limit would be very expensive.
The FAA notes that no known safety problem justifies that cost of
these design changes. However, the FAA is also aware that if warnings
of any type occur when the pilots know that no particular problem
exists, such warnings may become a nuisance. If warnings become a
nuisance, a pilot may disregard a warning when the airplane is
approaching a flight speed where an unsafe flight condition may occur.
Regulatory action is therefore needed to ensure that the warning will
occur within appropriate speed limits. Proposed Sec. 23.1303(e)(2)
would require manufacturers to establish a lower speed limit so that
nuisance overspeed warnings will not occur. The manufacturer would be
required to show that this limit is appropriate for the airplane design
but would not be required to set this lower limit at one specific
speed, such as VMO/MMO, which would be costly to achieve.
A new Sec. 23.1303(f) is proposed because attitude instruments are
available that provide a means accessible to the flightcrew members,
for adjusting the reference symbol through ranges that could result in
unsafe pitch angles in small airplanes. These instruments were
developed for airplanes that use high pitch angles for approved climb
or descent gradients. By permitting these airplanes to use instruments
that can be adjusted for these higher pitch angles, pilots are able to
maintain the design gradients using an instrument that provides a
normal indication at that pitch.
If such attitude instruments are installed in small airplanes,
pilots could adjust the reference symbol to ranges that could result in
unsafe pitch angles. The recommendation showed that some instruments
can be adjusted to result in pitch angles that are nearly the same as
the pitch angle that many small airplanes achieve before stalling. To
preclude potential cases of unwanted pitch adjustments of attitude
instruments installed in small airplanes, Sec. 23.1303(f) proposes to
limit the adjustment range to that limit that is needed for parallax
correction.
Proposed new Sec. 23.1303(g) would identify specific instruments,
and limits of those instruments, required for commuter category
airplanes. When the JAA initiated their consideration of commuter
category airplanes, one of the proposals they received recommended
adding the instrument requirements of Sec. 25.1303 to part 23 for
commuter category airplanes. In considering this recommendation, a
review of the requirements showed that many instruments required under
Sec. 25.1303 are presently required by the operating rules. In
addition, Sec. 23.1583(h) requires a list of the equipment that must be
installed for the kinds of operation for which the airplane is
approved. Based on the review, it was determined that many of the
requirements in Sec. 25.1303 would be redundant, and the recommendation
was not accepted.
In considering a portion of the recommendation to require a third
attitude instrument, the FAA noted that Sec. 91.531(a)(3) requires a
commuter category airplane of ten or more passengers to be operated
with a second-in-command and that Sec. 23.1321 requires flight and
navigation instruments for each required pilot. Accordingly, two
attitude instruments are required for a ten passenger, IFR approved
commuter category airplane. Service experience has shown that failures
of an attitude instrument system can occur where there will be a time
period in which the indicator appears to be working but is providing
incorrect information. During such a failure of one instrument in an
airplane equipped with only two instruments, the pilots may have
difficulty determining which instrument to follow, and hazardous flight
attitudes may result. A third attitude instrument would allow the crew
to retain reliable attitude information at all times, and thus the
proposed rule would require a third attitude instrument for commuter
airplanes operated by two pilots.

Section 23.1307 Miscellaneous Equipment

This proposal would remove the requirement of Sec. 23.1307(a) which
is being added to Sec. 23.785. The discussion of Sec. 23.785 covers
this change.
Also, the provisions of Sec. 23.1307(b)(1), (b)(2), and (b)(3), are
being removed from Sec. 23.1307. These requirements have been
previously added to Secs. 23.1361, 23.1351, and 23.1357, respectively;
therefore, they are redundant and may be removed. The designator for
paragraph (c) has also been removed from the remaining text of this
section.

Section 23.1309 Equipment, Systems, and Installations

Proposed new Sec. 23.1309(a)(4) would correct an inadvertent
omission that occurred when the FAA issued Amendment No. 23-41 (55 FR
43306, October 26, 1990). The omitted requirement was adopted by
Amendment No. 23-34 as a portion of Sec. 23.1309(d) and read: ``In
addition, for commuter category airplanes, system and installations
must be designed to safeguard against hazards to the airplane in the
event of their malfunction or failure.'' (52 FR 1833, January 15,
1987.) To correct this oversight, and to continue the single fault
provision of this paragraph, Sec. 23.1309(a)(4) is being proposed.

Section 23.1311 Electronic Display Instrument Systems

This proposal would revise Sec. 23.1311 to remove redundant
requirements and to clarify which secondary instruments are required
and the visibility requirements for these instruments. When
Sec. 23.1311 was adopted by Amendment No. 23-41 (55 FR 43306, October
26, 1990), several nonsubstantive changes were made to the proposals in
Notice No. 89-6 (54 FR 9345, March 6, 1989) to remove the redundancy
included in the notice. In the process certain provisions, such as the
one that permitted the installation of mechanical secondary
instruments, were inadvertently omitted from the final rule. Since the
final rule, discussions with airplane manufacturer representatives have
shown that the requirements defining the instrument panel location
where secondary instruments may be installed are also not clear.
Accordingly, the FAA is proposing to revise this section to correct and
clarify these portions.
Current Sec. 23.1311(a), which requires electronic display
indicator installations that are independent to each pilot station,
would be deleted because it is redundant with Sec. 23.1321(a). Section
23.1321(a) requires that each flight, navigation, and powerplant
instrument for use by any required pilot shall be located so that any
pilot seated at the controls can monitor the instruments with minimum
head and eye movement. As stated in the preamble of Notice No. 89-6 (54
FR 9345, March 6, 1989) regarding the proposed revision to
Sec. 23.1321, ``This revision also clarifies the rule relative to
instrumentation that must be provided for each pilot required for type
certification or by the applicable operating rules. If a pilot is
required by any applicable requirement, then that pilot must be
provided all instrumentation required for any operations for which the
airplane is approved.'' Accordingly, the requirements of current
Sec. 23.1311(a) would be removed.
In place of current paragraph (a), proposed Sec. 23.1311(a) would
be a revision of current paragraph (c) that would clarify what
instruments are required and the visibility of those instruments.
Proposed new Sec. 23.1311(a)(1) would require electronic display
instrument installations to meet the arrangement and visibility
requirements of Sec. 23.1321(a).
Proposed Sec. 23.1311(a) (2), (3), and (4) would be redesignated
with no changes from current Sec. 23.1311(c) (1), (2), and (3).
Proposed Sec. 23.1311(a)(5) would continue the requirement of
Sec. 23.1303(c) for a magnetic direction indicator and, in addition,
would require either an independent secondary mechanical altimeter,
airspeed indicator, and attitude indicator or individual electronic
display indicators for the altimeter, airspeed, and attitude that are
independent from the airplane's primary electrical power. These
secondary instruments may be installed in panel positions other than
the primary location as long as the selected location allows the pilot
to properly monitor the instruments and control the airplane.
The substance of proposed paragraph (a)(5) is both a substantive
change and a combination of the current Sec. 23.1311(b), which states
that certain electronic display indicators must be independent of the
airplane's electrical power system, and current Sec. 23.1311(c)(4)
which requires independent secondary attitude and rate-of-turn
instruments and specifies the location of those instruments. Proposed
Sec. 23.1311(a)(5) would delete the requirement for a rate-of-turn
instrument (in current Sec. 23.1311(c)(4)) and specify that the
required secondary instruments are those that provide altitude,
airspeed, magnetic direction, and attitude. The information that would
be provided by a secondary rate-of-turn instrument would not
appreciably add to the safe operations of the airplane if the pilot has
the information provided by the secondary attitude instrument.
Current Sec. 23.1311(b) requires that electronic display indicators
required by Sec. 23.1303 (a), (b), and (c) be independent of the
airplane's electrical power system. The original intent of the
requirement for secondary instruments, as stated in Notice No. 89-6,
was to require the installation of either mechanical instruments or
independent electronic display indicators powered by a source
independent of the airplane's electrical system. However, the current
rule does not clearly state this and does not address the installation
of mechanical instruments. Proposed Sec. 23.1311(a)(5), would allow
either secondary electronic display indicators or mechanical
instruments to provide a crew with information essential for continued
flight and landing in the event of failure in the airplane's electrical
power system.
Current Sec. 23.1311(c) (5) and (6) would be redesignated as
Sec. 23.1311(a) (6) and (7) without change.
Proposed new Sec. 23.1311 (b) and (c) would continue the
requirements of current Sec. 23.1311 (d) and (e) without change.

Section 23.1321 Arrangement and Visibility

The proposed revision to Sec. 23.1321(d) would remove the wording
that limits the instrument location requirement to airplanes
certificated for flight under instrument flight rules or airplanes
weighing more than 6,000 pounds. Instruments are for the pilot and
should be located near that pilot's vertical plane of vision without
regard to what flight rules are approved for the airplane's operation
or the maximum weight of the airplane.

Section 23.1323 Airspeed Indicating System

The proposed new Sec. 23.1323(c) would add a requirement that each
airspeed indicating system design and installation should provide
positive drainage of moisture from the system. This proposal is
consistent with the provisions required for a static system by
Sec. 23.1325(b).
If moisture enters, or accumulates in, an airspeed indicating
system, that moisture could cause erroneous airspeed indications or the
complete loss of airspeed information. The resulting loss of accurate
airspeed information would be hazardous to the operation of the
airplane; therefore, to assure the safety of the airplane, the FAA
would need to apply the more general airworthiness requirements of
Secs. 23.1301 and 23.1309 to such a system and require provisions for
drainage of moisture. Accordingly, this proposed revision of the
airspeed indicating systems requirements only clarifies the criteria
that must be applied to airspeed indicating systems.
To better organize the requirements that are applicable to the
airspeed systems on all airplane categories and those that would be
additional requirements for the airspeed systems of commuter category
airplanes, the FAA proposes to redesignate existing paragraphs (c) and
(e), respectively, as paragraphs (e) and (d). By this redesignation,
paragraphs (a), (b), (c), and (d) would apply to all airplanes, and
paragraphs (e) and (f) would include additional requirements applicable
to commuter category airplanes.
The proposal for redesignated paragraph (e) would also remove the
words ``in flight and'' from the first sentence of that paragraph. This
would remove the requirement for the airspeed indicating system to be
calibrated in flight. The requirement for an in flight calibration is
provided in paragraph (b). Proposed redesignated paragraph (e) would
apply to the calibration needed to determine the system error during
the accelerate-takeoff ground run.
As identified in the background section of this notice, the FAA is
issuing additional notices that address proposed changes to the
requirements for powerplant, flight, and airframe. Proposed revisions
to subpart G in the flight NPRM include placing all of the requirements
for what must appear in the Airplane Flight Manual (AFM) in that
subpart. With the proposals to revise the AFM requirements, the flight
NPRM also proposes that the requirement in existing Sec. 23.1323(d) (to
show the relationship between IAS and CAS in the AFM) be added to
Sec. 23.1587 as proposed new paragraph (d)(10). Because the AFM
requirement would be added to Sec. 23.1587, it no longer needs to
appear in Sec. 23.1323. Accordingly, this notice proposes to remove the
text of existing Sec. 23.1323(d).
Proposed new Sec. 23.1323(f) would provide that, on those commuter
airplanes where duplicate airspeed indicators are required, the
airspeed pitot tubes must be located far enough apart so that both
tubes will not be damaged by a single bird strike.

Section 23.1325 Static Pressure System

Current Sec. 23.1325(b)(3) establishes certain static pressure
system requirements for airplanes that encounter icy conditions.
Current Sec. 23.1325(g) exempts from the requirements of (b)(3)
airplanes that are prohibited from flight in instrument meteorological
conditions in accordance with Sec. 23.1559(b). After the adoption of
Sec. 23.1325(g), it came to the FAA's attention that there are
conditions other than instrument meteorological conditions where icing
may be encountered and, therefore, that this paragraph should also
exempt from the provisions of Sec. 23.1325(b)(3) airplanes that are
prohibited from flight in icing conditions. Accordingly,
Sec. 23.1325(g) would be revised to read, ``For airplanes prohibited
from flight in instrument meteorological or icing conditions.''
As indicated in the background section of this notice, the FAA will
issue additional notices that will address proposed changes to the
requirements for powerplant, flight, and airframe. Revisions to Subpart
G in the flight notice will propose to place all of the requirements
that specify what must appear in the AFM in that subpart. With the
proposals to revise the AFM requirements, the flight notice will also
propose that Sec. 23.1325(f) be removed and the results of the
altimeter system calibration would be required by Sec. 23.1587.

Section 23.1326 Pitot Heat Indication System

Proposed new Sec. 23.1326 would require the installation of a pitot
tube heat indicating system on those airplanes required to be equipped
with a heated pitot tube. Heated pitot tubes ensure that moisture will
not freeze in the tube and block or partially block the airspeed
indicating system. Such blockage would result in the pilots receiving
incorrect flight data with possibly disastrous results.
Due to advancements in technology, many part 23 airplane
installations now utilize equipment whose data sources are critical to
the accurate and dependable operation of that equipment. The heated
pitot tube is one such data source. The pitot heat indicating system
will advise the pilots of any inoperative heating element in the pitot
tube and that subsequent inaccuracies may result.
Part 23 airplanes certificated for flight under instrument flight
rules or for flight in icing conditions are required by current
Sec. 23.1323(e) to have a heated pitot system or an equivalent means of
preventing an airspeed indicating system malfunction due to ice
accumulation. This proposal would require such airplanes equipped with
a heated pitot tube to be equipped with a pitot tube heat indicating
system. This requirement will provide greater assurance that the pilots
will not be dangerously misled by faulty flight instrument indications
caused by pitot tube icing.
When pitot tube heat indicating system requirements were added to
part 25, the FAA noted the occurrence of at least one accident and
several incidents in which an airspeed indicating error occurred that
might have been avoided if a pitot tube heat indicating system had been
installed. Part 23 airplanes operate at lower airspeeds and over
shorter distances that do part 25 airplanes; therefore, their exposure
to moisture and temperature conditions where icing may occur is higher
than it is for transport category airplanes. Because of this
environmental exposure, the potential for an inoperative heated pitot
tube becoming a hazard to part 23 airplanes is greater.
This proposed requirement also responds to National Transportation
Safety Board (NTSB) recommendation A-92-85, which recommends requiring
a modification to certain part 23 airplanes to provide for a pitot heat
operating light similar to the light required by Sec. 25.1326 for
transport category airplanes. NTSB issued the safety recommendation,
among others, as a result of a special investigation and analysis of a
series of fatal accidents that occurred from May 31, 1989, through
March 17, 1991.

Section 23.1329 Automatic Pilot System

New Sec. 23.1329(b), adopted by Amendment No. 23-24 (58 FR 18958,
April 9, 1993), does not state clearly that stick controlled airplanes
must be equipped with the same autopilot quick release controls that
are required for airplanes with control wheels. This proposed revision
of Sec. 23.1329(b) would clarify that a quick release control must be
installed on each control stick of an airplane that can be operated
from either pilot seat.

Section 23.1337 Powerplant Instruments Installation

This proposal would revise the heading of this section to reflect
the powerplant instrument installation requirements that it contains.
The difference between this section and Sec. 23.1305 is clarified by
this change.
Section 23.1337(b) would be revised by removing the wording that
authorizes installation of only those fuel indicators marked in gallons
and pounds. In countries that use the metric system, other acceptable
units of measure for marking fuel indicators are used. This proposed
revision would allow the use of any appropriate measurement unit.
Section 23.1337(b) would also be revised by adding the word
``usable'' to the first sentence of this section. This revision is
consistent with the requirements of Sec. 23.1337(b)(1), which requires
the fuel quantity indicator to be calibrated to read ``zero'' when the
fuel in the tank is equal to the unusable fuel determined under
Sec. 23.959.
Proposed new Sec. 23.1337(b)(4) would require a ``means to
indicate'' the amount of usable fuel in each tank when the airplane is
on the ground. This requirement would ensure that a reliable means is
provided for the pilot to determine before takeoff that the amount of
fuel that is in the airplane is adequate for the intended flight. The
ability to make this preflight determination will help reduce the
number of accidents that have resulted from fuel starvation. This
proposal, which is patterned after Sec. 23.1337 (d) and (d)(1), would
not require a separate fuel indicating system. The means to determine
the amount of fuel while on the ground may be provided by a calibrated
dipstick, separate markings on the inflight fuel indicator, or any
other acceptable means selected by the manufacturer. Accordingly, this
proposal would contribute to the safe operation of the airplane and
would not appreciably add to the cost of the airplane design.

Section 23.1351 General

The proposal would revise current Sec. 23.1351 by removing portions
of paragraphs (b)(2) and (b)(3) and by removing all of paragraph
(b)(4). The removed requirements are applicable to alternators that
depend upon the battery for initial excitation or for stabilization.
This revision responds to a Joint Aviation Authority recommendation to
remove the provisions that allow a battery failure to result in the
loss of the alternator. Information in this recommendation showed that
self-excited alternators are now available for installation on newly
certificated airplanes. The FAA has verified that self-excited
alternators are now available; therefore, there is no longer a need for
the regulations to address alternators that depend upon a battery for
initial excitation and stabilization.
Revised Sec. 23.1351(c)(3) would require an automatic means for
reverse current protection. Reverse current protection is accomplished
by means that automatically detect changes in the current. The proposed
revised wording would more accurately define this function and the
equipment that would accomplish the protection.
Finally, Sec. 23.1351(f) would be revised by adding a requirement
that would require the ground power receptacle to be located where its
use will not result in a hazard to the airplane or to people on the
ground using the receptacle.

Section 23.1353 Storage Battery Design and Installation

Proposed new Sec. 23.1353(h) would require that, in the event of a
complete loss of the primary electrical power generating system,
airplane battery capacity must be sufficient to supply at least 30
minutes of electrical power to those loads essential to the continued
safe flight and landing of the airplane.
This proposal is not limited to airplanes that are approved for any
particular type of operation. Although the battery capacity needed for
an airplane approved for day visual flight rules (VFR) operations would
be much less than the capacity for an airplane approved for day/night
instrument flight rules (IFR) operations, the same level of safety
should be provided for all airplanes. While this proposal would add an
additional requirement to part 23 for normal, utility, acrobatic, and
commuter category airplanes, in practice this requirement to provide a
battery capacity sufficient to supply at least 30 minutes of electrical
power is not new to many airplane manufacturers. Certain other
countries in which part 23 airplanes have been certificated have
requirements for such a 30-minute battery capacity. Manufacturers'
experience with these requirements has shown that the only design
impact that results from complying with these requirements is the need
to install a battery with greater capacity than might otherwise be
installed. Experience has also shown that a load shedding procedure may
be necessary for certain airplanes. No other airplane design changes
would be needed.
Despite the above referenced experience record, this requirement
would be new to some manufacturers and they may have questions on how
it would be applied. For that reason, this notice discusses compliance
considerations that have emerged from experience based on substantively
equivalent requirements.
This compliance experience has shown that the rating of the battery
selected for the airplane should be sufficient to cover the loss of
capacity that would occur with battery age and the reduced capacity
that results from a realistic state of charge, which may be less than a
full charge. Using a design battery capacity that is only 75 percent of
the battery nameplate rating would be an acceptable way of accounting
for these losses.
In addition to determining the battery rating that would be needed,
the manufacturer would also need to determine the functions that would
be necessary for 30 minutes of safe flight and the landing of the
airplane. Again, experience has identified several functions. For a day
VFR approved airplane, no functions may require battery power; however,
it may be necessary to supply power for certain communication
capacities or, if the airplane has electrically powered retractable
landing gear, power may be required to lower the gear. Providing a
secondary means for lowering the gear would be an acceptable
alternative to providing electrical power or battery power for this
function.
For other types of operating approvals, providing power for the
following functions and equipment should be considered:
1. Any required flight and navigation instruments. Air driven
instruments that would function over the required period can also be
accepted for this function.
2. Cockpit and instrument lighting.
3. For IFR and icing approvals, power for the heated pitot tube.
4. For radio communication, usually one VHF communication system
with power for three to five minutes of transmission would be
acceptable.
5. Functions needed for safe night flight and night landing of the
airplane.
6. Electronic engine ignition systems.
7. Any functions that cannot be readily shed following the loss of
generator power.
8. Engine inlet heat or deicing protection required for normal
operation of the airplane.
Although power for the listed functions may provide for the safe
operation and landing of most airplanes, individual airplane designs
may require the consideration of additional functions.
In applying these rules it may be assumed that airframe and engine
icing protection equipment would not be operating at the time of the
generator system failure. Power for icing protection would not be
required if the icing protection equipment is not required for the
normal operation of the airplane.
This proposal would require additional battery capacity and would
not alter or supersede any other requirements in this part for separate
or dedicated emergency power supplies. When requirements such as those
in current Sec. 23.1331(a) or in proposed Sec. 23.1311(a)(5) are
applicable to the airplane design, these power supplies are required to
provide a needed level of safety for that function; therefore, that
power source must be supplied.

Section 23.1359 Electrical System Fire Protection

Proposed new Sec. 23.1359 would require smoke and fire protection
for electrical system installations. The provisions of Sec. 23.1359(a)
of this proposal state that electrical systems must meet the applicable
requirements of Secs. 23.863 and 23.1182.
Proposed Sec. 23.1359(b) would require that the electrical systems
components installed in designated fire zones and used during emergency
procedures be fire resistant. This provision is needed to clarify the
requirements for electrical system components that may be installed in
the designated fire zones identified in Sec. 23.1181.
Finally, Sec. 23.1359(c) provides burn criteria for electrical wire
and cables. A proposed revision to appendix F of part 23 that would add
appropriate wire testing criteria is included in this notice.
This proposed burn criteria for wire is necessary because of the
increased use of electrical systems in the design of part 23 airplanes
and the resulting increase in the amount of electrical wire being
installed. This increased use results in the need to ensure that wire
insulating material does not become the source of an in-flight fire
and/or that it does not propagate a fire from another source. The
electrical wire burn requirements in this proposal, along with the
testing identified in revised appendix F, would ensure that installed
electrical wire has insulating material that reduces the possibility of
hazardous in-flight fires.

Section 23.1361 Master Switch Arrangement

To harmonize with the JAR this proposal would revise
Sec. 23.1361(c) by making an editorial change to remove the last two
words of the paragraph that read ``in flight.''

Section 23.1365 Electrical Cables and Equipment

This proposal would revise Sec. 23.1365(b) and would add three new
paragraphs.
Section 23.1365(b) would be revised in relation to proposed new
Sec. 23.1359(c), which would require self-extinguishing insulated
electrical wires and cables. Current Sec. 23.1365(b) requires that
cable and associated equipment that would overheat in the event of
circuit overload or fault must be flame resistant and may not emit
dangerous quantities of toxic fumes. The proposed revisions to
Sec. 23.1365(b) would remove the reference to electrical cables from
the flame resistance requirement since the cables would be required to
have self-extinguishing insulation under Sec. 23.1359(c). The
requirement for electrical cables and the associated equipment that
would overheat to not emit dangerous quantities of toxic fumes has been
retained.
The text of Sec. 23.1365(b) that includes the words ``at least
flame resistant '' would also be revised by removing the words ``at
least''. The removed words implied that there were burn requirements,
other than the ones in this section, that must be met.
The three paragraphs that would be added by this proposal would
require: (1) The identification of electrical cables, terminals, and
connectors; (2) the protection of electrical cables from damage by
external sources; and (3) installation criteria for cables that cannot
be protected by a circuit protection device.
As identified in the discussion of proposed Sec. 23.1359, there is
an increasing use of electrical systems in part 23 airplanes. The
resulting increase in the number of electrical wires used in part 23
airplanes makes proper installation difficult. The proposal for
electrical cable identification would provide better assurance that the
cables will be correctly installed initially and correctly reinstalled
when airplane maintenance or modifications are accomplished. The other
proposed new requirements would provide installation criteria that will
ensure the protection of cables under circumstances that can be
expected from the increased use of electrical systems.

Section 23.1383 Taxi and Landing Lights

The landing light requirements of Sec. 23.1383 would be revised by
adding taxi lights to this section. When the landing light requirements
were included in the normal, utility, acrobatic, and commuter category
requirements, the same lights were used for both night landing and
taxiing of the airplane. Due to availability of different types of
lights, separate lights are now frequently installed for landing and
for taxiing. Including the word ``taxi'' in the heading would clarify
that the requirements cover both kinds of lights.
Current Sec. 23.1383(a), which requires the lights to be
acceptable, would be deleted because it is unnecessary to state this.
All lights that are found to meet the requirements of this section and
other directly related airworthiness requirements are acceptable. The
paragraphs would be redesignated accordingly.
Current Sec. 23.1383(b)(3) requires that a landing light must be
installed to provide enough light for a night landing. Proposed
Sec. 23.1383(c) would revise ``night landing'' to ``night operation''
since the requirements would also cover taxiing and parking. Proposed
new paragraph (d) would require the lights to be installed so that they
do not cause a fire hazard. This clarifies the need for such an
evaluation.

Section 23.1401 Anticollision Light System

This proposal would revise Sec. 23.1401 to require the installation
of an anticollision light system on all part 23 airplanes. Current
Sec. 23.1401 requires an anticollision light system only if
certification for night operations is requested. When the requirements
for anticollision lights were first added to the Civil Air Regulations
(CAR), part 3, in 1957, those requirements were needed to increase the
conspicuity of the airplanes during night operations because of the
increasing air traffic density and the newer airplanes' capability to
attain higher speeds. At the time, the operating conditions did not
show a need for such lights for daylight operations.
The number of airplanes that have been added to the fleet and the
increasing speeds resulting from improved technology, especially the
increasing use of turbine engines, now necessitates the conspicuity
provided by anticollision lights for day operations as well. The FAA
Accident and Incident data for the period 1984 through 1990 shows that
269 aircraft were involved in midair collisions in which 108 fatalities
occurred. A review of this data shows that 234 of these aircraft were
involved in accidents or incidents that occurred during VFR conditions
and that 224 were involved in accidents or incidents during day
operations. The other 10 were involved in operations at night or dusk.
The reports on 35 aircraft did not identify the type of condition that
existed.
Of the types of aircraft identified by the reports in this data, 60
were balloons, gliders, or other aircraft that were not certificated
under part 23 and whose level of safety would not be changed by this
proposal. When the data is revised by removing those reports, it shows
that 209 small, part 23 airplanes operated under VFR conditions were
involved in midair accidents or incidents and that at least 167 of
these airplanes were being operated in day VFR conditions. Because the
occupant capacity of all the aircraft in the data ranged from one to
ten, it can be assumed that the fatality rate of .401 per aircraft (108
fatalities/269 aircraft) would be nearly the same for the 167 small
airplanes operating in day VFR conditions as it was for the 269
aircraft. Based on this assumption, there would have been approximately
67 fatalities that occurred in these 167 small airplane accidents and
incidents.
The reports do not show if the airplanes involved were equipped
with or were using anticollision lights. They do show that a need
exists to reduce the number of accidents. Requiring the installation of
anticollision lights on all newly certificated airplanes and, as
proposed by revised Sec. 91.209 in this notice, requiring operation of
anticollision lights during day operations would increase the
airplane's conspicuity and contribute to a reduction in the number of
accidents. Even if such action is only 25 percent effective, a review
of the 6-year service history indicates that approximately 17
fatalities could be avoided in a similar 6-year period. Many
manufacturers have realized the additional safety that can be provided
by the increased airplane conspicuity of using anticollision lights and
have elected to install an anticollision light system on all of the
airplanes they produce. Therefore, most airplanes are now being
manufactured with an installed anticollision light system, and the FAA
expects that this proposal would not result in an economic burden on
the aviation community.

Section 23.1431 Electronic Equipment

This proposal would add three new paragraphs to Sec. 23.1431.
Proposed new paragraph (c) would require that airplanes required to be
operated by more than one flightcrew member must be evaluated to
determine if the flightcrew members can converse without difficulty
when they are seated at their duty stations. Accident investigations
have shown that, in some instances, conversation between the flightcrew
members was severely hindered by the noise level in the cockpit and
that the inability to communicate contributed to the accident. If the
required evaluation shows that the noise level does not impair
conversation, no further action is required. However, if the evaluation
shows that conversation will be difficult, an intercommunication system
would be required.
Proposed new paragraph (d) would require that if installed
communication equipment includes any means of switching from receive to
transmit, the equipment must use ``off-on'' transmitter switching that
will ensure that the transmitter is turned off when it is not being
used. Transmitting equipment that remains in the transmit mode when not
being used blocks the frequency being used and can create an unsafe
condition by preventing other needed communication.
Proposed new paragraph (e) would require that if provisions for the
use of communications headsets are provided, it must be demonstrated
that flightcrew members can hear aural warnings when a headset is being
used. Aural warnings are required to warn the pilot of a condition that
necessitates the pilot's taking action; therefore, it is necessary to
ensure that such warnings would be effective even when headsets are
being used.
During the development of the proposed new requirements in
paragraphs (c) and (e), the FAA considered proposing a requirement that
compliance demonstrations should be conducted under actual cockpit
noise conditions when the airplane is being operated. The FAA, however,
ultimately determined that such a requirement could result in
demonstrations conducted under more severe noise conditions than
needed. Accordingly, no such requirement is being proposed. If the FAA
determines in the future that noise conditions for demonstrations need
to be specified, the FAA will define these conditions in advisory
material.

Section 23.1435 Hydraulic Systems

Since the close of the comment period for the Small Airplane
Airworthiness Review Program Notice No. 3 (55 FR 40598, October 3,
1990), now adopted by Amendment No. 23-43 (58 FR 18958, April 9, 1993),
the FAA has been involved in discussions of the installation of
hydraulic accumulators that are permitted by Sec. 23.1435(c). These
discussions have shown that applicants are likely to find
Sec. 23.1435(c) difficult to understand because of the way it is
worded. This notice would further revise Sec. 23.1435(c) to clarify
under what circumstances a hydraulic accumulator and reservoir may be
installed on the engine side of any firewall.

Section 23.1447 Equipment Standards for Oxygen Dispensing Units

Proposed new Sec. 23.1447(a)(4) would require that if radio
equipment is installed in an airplane, flightcrew oxygen dispensing
units must be designed to allow the use of communication equipment when
oxygen is being used. If radio equipment is installed, that equipment
cannot perform its intended function if the flightcrew is not provided
the proper means for its utilization under all operating conditions,
including operations when oxygen is being used.
This proposal would not require all flightcrew oxygen dispensing
units to be equipped with communication equipment. Since an airplane
may be operated in uncontrolled airspace, where two-way radio
communication is not required and, at the same time, be at altitudes
where oxygen is required for the flightcrew members, some airplanes
have a crew oxygen system but no radio equipment. It would be
inappropriate to require the flightcrew dispensing units of those
airplanes to be equipped with communication equipment.
The proposed revisions to Sec. 23.1447(d) would require the
flightcrew oxygen dispensing units to be automatically presented before
the cabin pressure altitude exceeds 15,000 feet or be the quick-donning
type if the airplane is certificated for operation above 25,000 feet.
The requirement in paragraph (e) for the passenger dispensing units to
be automatically presented if the airplane is approved for operation
above 30,000 feet has not been revised. The revision to paragraph (d)
would provide the flightcrew and the airplane passengers the same level
of safety as provided by other airworthiness standards. This proposed
revision is also consistent with the proposed revision of Sec. 23.841
in this notice.

Section 23.1451 Fire Protection for Oxygen Equipment

This proposed new section would specify that fire protection is
needed for oxygen equipment installations. Section 23.1451 (a) and (b)
would, respectively, prohibit the installation of oxygen equipment in
designated fire zones and require that oxygen system components be
protected from the heat from designated fire zones.
Proposed Sec. 23.1451(c) would require oxygen equipment and lines
to be separated from other equipment or to be protected in a manner
that would prevent escaping oxygen from striking grease, fluids, or
vapors. The impingement of pure oxygen on certain materials will lower
their combustion point to a value where ignition will occur in ambient
conditions thereby creating a potential source for an airplane fire. In
one instance, an airplane was destroyed by fire that resulted when
escaping oxygen impinged on lubricating material during maintenance of
the airplane. The proposed new section would ensure that oxygen systems
are protected to prevent fire hazards that can result from escaping
oxygen.

Section 23.1453 Protection of Oxygen Equipment From Rupture

Section 23.1461 Equipment Containing High Energy Rotors

This proposal would revise paragraph (a) of this section to clarify
that the requirements apply to high energy rotors included in an
auxiliary power unit (APU). Following the addition of this section to
part 23, the FAA issued a policy message that showed Sec. 23.1461 was
adopted to cover equipment such as APU's and constant speed drives that
may be installed on small airplanes. The proposed revision of paragraph
(a) will clarify the applicability of this section as identified in
that policy material.

Appendix F

This proposal would revise appendix F to provide the procedures
needed to test electrical wire to ensure that the wire meets the burn
requirements of Sec. 23.1359. It would also add procedures for meeting
the 45 degree and 60 degree angle burn test requirement proposed for
Secs. 23.855(c)(2) and 23.1359(c), respectively. Paragraph (b) would be
revised to clarify the specimen configuration that must be used in the
testing procedures that are proposed to be added by this notice.

Section 91.205 Powered Civil Aircraft With Standard Category U.S.
Airworthiness Certificates: Instrument and Equipment Requirements

Proposed new Sec. 91.205(b)(11) would require that airplanes
certificated under Sec. 23.1401 of this notice be equipped with an
anticollision light system for day VFR operations. Day VFR operations
are discussed under Sec. 23.1401 of this notice.

Section 91.209 Aircraft Lights

Proposed new Sec. 91.209(b) would require that airplanes equipped
with an anticollision light system be operated with the anticollision
light system lighted during all types of operations, except when the
pilot determines that, because of operating conditions, it would be in
the interest of safety to turn the lights off.

Regulatory Evaluation, Regulatory Flexibility Determination, and Trade
Impact Assessment

Proposed changes to Federal regulations must undergo several
economic analyses. First, Executive Order 12866 directs that each
Federal agency shall propose or adopt a regulation only upon a reasoned
determination that the benefits of the intended regulation justify its
costs. Second, the Regulatory Flexibility Act of 1980 requires agencies
to analyze the economic effect of regulatory changes on small entities.
Third, the Office of Management and Budget directs agencies to assess
the effects of regulatory changes on international trade. In conducting
these analyses, the FAA has determined that this rule: (1) Would
generate benefits that would justify its costs and is not a
``significant regulatory action'' as defined in the Executive Order;
(2) is not ``significant'' as defined in DOT's Policies and Procedures;
(3) would not have a significant impact on a substantial number of
small entities; and (4) would not constitute a barrier to international
trade. These analyses, available in the docket, are summarized below.

Regulatory Evaluation Summary

This section summarizes the costs and benefits of each provision of
the proposed rule. Many of the provisions would impose either no cost
or a negligible cost. Such provisions are typically administrative,
editorial, clarifying, relieving, or conforming in nature. In addition,
the FAA holds that certain provisions have a potential safety benefit
that can be achieved with no incremental cost, due primarily to the
fact that this rule would apply to future certificated airplanes and
retrofitting would not be required. All provisions of the proposed
rule, including those with no or negligible costs, are summarized
below. Only those provisions with non-negligible costs are further
evaluated in the section that follows. The reader is directed to the
full regulatory evaluation for additional information.

----------------------------------------------------------------------------------------------------------------
Section Incremental cost Benefit
----------------------------------------------------------------------------------------------------------------
Section 23.677Trim systems........... Negligible.......................... Safety.
Section 23.691 Artificial stall None................................ Administrative.
barrier system.
Section 23.697Wing flap controls..... $480 per certification and $100 per Nominal safety and relief.
airplane for affected airplanes.
Section 23.701Flap interconnection... None................................ Clarification.
Section 23.703Takeoff warning system. $240 per certification for Nominal safety and relief.
evaluation. Where necessary, $5,120
per certification, $1,000 per
airplane and $100 per year.
Section 23.723Shock absorption tests. None................................ Editorial.
Section 23.729Landing gear extension (e). None.......................... Clarification.
and retraction system.
(g). Negligible, general practice.. Minor; general practice.
Section 23.735Brakes................. (a). None.......................... Editorial clarification.
(c). None.......................... Administrative.
(e). $240 per certification........ Minor safety.
Section 23.745Nose/Tail wheel None................................ Minor. Avoids special conditions.
steering.
Section 23.775Windshields and windows (a). None.......................... Relieving.
(c). None.......................... Clarification.
(h). Up to $350,000 per Safety.
certification.
Section 23.783Doors.................. (b). None.......................... Minor safety.
(f). $25 per airplane.............. Safety.
Section 23.785Seats, births, litters, None................................ Editorial organization.
safety belts and shoulder harnesses.
Section 23.787Baggage and cargo (a). $1 per airplane............... Minor safety.
compartments.
(b). $60 per certification and up Safety.
to $100 per airplane.
(c). None.......................... Clarification.
Section 23.791Passenger information $60 per certification, up to $200 Safety.
signs. per airplane, and a negligible
effect on operating costs.
Section 23.807Emergency exits........ (a)(4). Expected negligible........ Minor safety.
(b) and (b)(5). None............... Clarification and editorial.
(b)(6). Where chosen, $10,000 per Safety.
certification and $500 per airplane.
Section 23.841Pressurized cabins..... $1,000 per certification and $2,000 Safety.
per airplane.
Section 23.853Passenger and crew None................................ Editorial.
compartment interiors.
Section 23.855Cargo and baggage (a). Less than $40 per airplane.... Minor safety.
compartment fire protection.
(b). Less than $200 per airplane... Safety.
(c). Potentially as high as $1,800 Safety.
per certification, $4,550 per
airplane, and $100 per year.
Section 23.867Electrical bonding and None................................ Editorial.
protection against lightning and
static electricity.
Section 23.1303Flight and navigation Introduction. None.................. Clarification.
instruments.
(d). $500 per certification and Safety.
$350 per airplane.
(e)(2). None....................... Minor safety.
(f). None.......................... Minor safety.
(g)(1). Up to $2,000 per airplane.. Safety.
(g)(2). None....................... Minor safety.
(g)(3). Up to $3,600 per Safety.
certification and $7,000 per
airplane.
Section 23.1307Miscellaneous None................................ Editorial and conforming.
equipment.
Section 23.1309Equipment, systems, None................................ Minor safety.
and installations.
Section 23.1311Electronic display None................................ Clarifying, editorial, and
instrument systems. relieving.
Section 23.1321Arrangement and None................................ Minor safety.
visibility.
Section 23.1323Airspeed indicating None................................ Minor safety.
system.
Section 23.1325Static pressure system None................................ Relieving.
Section 23.1326Pitot heat indication $2,800 per certification, $1,600 per Safety.
system. airplane.
Section 23.1329Automatic pilot system None................................ Clarifying.
Section 23.1337Powerplant instruments Heading and (b). None.............. Clarifying, relieving.
installation.
(b)(4). Negligible................. Safety.
Section 23.1351General............... (b). None.......................... Administrative.
(c)(3). None....................... Clarifying.
(f). None.......................... Minor safety.
Section 23.1353Storage battery design Where necessary, up to $30 per five Safety.
and installation. years capital, up to $10 per year
operating, and $600 per
certification.
Section 23.1359Electrical system fire (a). None.......................... Clarifying emphasis.
protection.
(b). Negligible.................... Clarifying.
(c). $240 per certification........ Safety.
Section 23.1361Master switch None................................ Editorial.
arrangement.
Section 23.1365Electrical cables and (b). None.......................... Conforming editorial.
equipment.
(d). $4,400 per certification and Safety.
$100 per airplane.
(e). None.......................... Minor safety.
(f). Negligible.................... Minor safety.
Section 23.1383Taxi and landing None................................ Editorial update.
lights.
Section 23.1401Anticollision light Where necessary, $2,400 per Safety.
system. certification and $1,600 per
airplane.
Section 23.1431Electronic equipment.. (c). Where necessary, up to $1,200 Safety.
per certification and $1,600 per
airplane.
(d). Negligible. Included above.... Minor safety.
(e). None or negligible............ Safety.
Section 23.1435Hydraulic systems..... None................................ Clarifying.
Section 23.1447Equipment standards (a)(4). Up to $2,000 per airplane.. Safety.
for oxygen dispensing units.
's (d) and (e). None............... Minor safety.
Section 23.1451Fire protection for None................................ Safety.
oxygen equipment.
Section 23.1453Protection of oxygen $960 per certification.............. Safety.
equipment from rupture.
Section 23.1461Equipment containing None................................ Clarifying.
high energy rotors.
Appendix F to part 23--Test procedure None. Considered above.............. Minor safety.
Section 91.205Powered civil aircraft None................................ Safety, considered above.
with standard category U.S.
airworthiness certificates:
Instrument and equipment
requirements.
Section 91.209Aircraft lights........ $25 per year per airplane........... Safety, considered above.
----------------------------------------------------------------------------------------------------------------

Evaluation of Provisions With Non-Negligible Projected Costs

This section describes and evaluates those provisions of the
proposed rule that are expected to impose costs that are not
negligible.

Section 23.697 Wing Flap Controls

Proposed new Sec. 23.697(c) would provide safety standards for the
wing flap control lever designs installed in airplanes that use wing
flap settings other than fully retracted when showing compliance with
Sec. 23.145. The FAA estimates that an aerospace engineer could design
the flap control lever to meet the proposed requirement in 8 hours at a
burdened rate of $60 per hour, totalling $480 per certification. The
control lever itself would impose an incremental cost, including
installation, of approximately $100 per airplane.
The nominal benefits of this provision would derive from the
increased safety afforded the pilot in positively selecting the proper
flap setting to maintain longitudinal control. In fact, if a flap
position other than fully retracted were needed to maintain
longitudinal control: (1) That position would be necessary to prevent
an unsafe condition, (2) the airplane would not be certificated under
that design, and (3) the airplane would have to be redesigned so that
intermediate flap positions would not be needed for control. Proposed
paragraph (c) would allow the identification of an intermediate flap
position and the positive means of selecting that position. This
alternative would rectify the unsafe condition without requiring the
manufacturer to redesign the airplane.

Section 23.703 Takeoff Warning System

This proposed new section would require a takeoff warning system on
some commuter category airplanes. The requirement would be applicable
if the flight evaluation shows that an unsafe takeoff condition would
result if lift devices or longitudinal trim devices are set to any
position outside the approved takeoff range. If the evaluation shows
that no unsafe condition would result at any setting of these devices,
a takeoff warning system would not be required. For those airplanes on
which a warning system must be installed, the proposed rule would
provide requirements for the installation of the system.
The FAA estimates that an evaluation to determine whether a takeoff
warning system would be needed would cost $240 (4 hours of engineering
at a burdened rate of $60 per hour). Where needed, the integration
design of a warning system would cost $2,400 (40 hours at $60 per
hour). In addition, an incremental 4 hours of flight testing at a cost
of $2,720 ($500 per hour for two test pilots and $180 per hour for
fuel) would be needed to demonstrate the system's performance. The FAA
estimates that the system, including acquisition, wiring, micro
switches, and labor, would add approximately $1,000 to the cost of each
airplane required to have one. Maintenance of such a system would cost
approximately $100 per year. The FAA solicits comments from interested
parties concerning the expected certifications that would require a
takeoff warning system and the concomitant costs to acquire, install,
and maintain them.
The nominal benefits of this proposal would derive from the
increased safety provided by the takeoff warning system that would
activate whenever lift or longitudinal trim devices are not set within
their approved takeoff ranges. In fact, if an evaluation showed that
positions of the lift or longitudinal trim devices could create an
unsafe condition on takeoff, the manufacturer would be required, under
existing regulations, to redesign the devices so that the unsafe
positions could not be obtained. The proposed section would provide
relief by allowing the applicant to install a warning system rather
than redesigning the trim device(s).

Section 23.735 Brakes

Proposed new Sec. 23.735(e), applicable to commuter category
airplanes, would require establishing the minimum rejected takeoff
brake kinetic energy capacity rating of each main wheel brake assembly.
Section 23.45 provides that the determination of the accelerate-stop
distance for commuter category airplanes be made in accordance with the
applicant's procedures for operation in service. This proposed
requirement is needed to ensure that the brakes will perform safely
under accelerate-stop conditions.
Under the proposed rule, manufacturers of commuter airplanes could
determine the kinetic energy absorption requirements either through a
conservative rational analysis of the sequence of events expected
during a rejected takeoff or by using a formula presented in proposed
new Sec. 23.735(e)(2). It is projected that the necessary determination
would cost $240 based on four hours of engineering at a burdened rate
of $60 per hour. The potential benefits of the proposal would derive
from the added safety that would be provided by establishing beforehand
the minimum necessary kinetic energy capacity rating of each main wheel
brake assembly under rejected-takeoff conditions.

Section 23.775 Windshields and Windows

Introductory text and paragraph (h)(1) would be added to require
that commuter category windshield panes that are directly in front of
the pilots be able to withstand the impact of a two pound bird at
maximum approach flap speed. By requiring full protection against the
strike of a two-pound bird at approach speed, additional protection
would also be provided if the airplane strikes a larger bird or strikes
a bird at a higher speed.
Proposed Sec. 23.775(h)(2) would further require the panels of the
windshield to be so arranged that, if one is damaged, other panels
would remain to provide visibility for continuous safe flight and
landing.
The potential costs of proposed Sec. 23.775(h) would vary depending
on the circumstances of the affected manufacturer. Industry sources
estimate that the total nonrecurring cost per model would range from
$250,000 to $350,000, consisting of: (1) Up to $200,000 for a bird
strike test article (``bird gun'') if the manufacturer does not have
one; and (2) up to $150,000 of time and materials costs for the actual
testing.
A manufacturer that has a bird strike test article would not incur
additional capital test costs. Most manufacturers would incur up to
$150,000 in time and materials costs for the actual testing, but even
these costs would be mitigated by the existing need of most
manufacturers to perform such tests for export sales to JAA member
countries.
Industry sources estimate that there would be no identifiable
increment in design or tooling costs since the windshield would be an
integral part of the initial design. Similarly, little or no recurring
costs per airplane (incremental materials, installation, or weight) are
projected since it is reasonable to assume that the pressure load, as
compared to bird strike resistance, would be the controlling factor in
the windshield design strength.
The benefit of the proposed rule is the incremental protection
against bird strikes that would be afforded to commuter category
airplanes. The FAA has reviewed International Civil Aviation
Organization (ICAO) data on bird strikes that occurred on member-
country airplanes of 19,000 pounds or less than 1981 through 1989.
These data show that approximately 550 strikes occurred and that one
out of seven strikes hit the windshield. The data show that:
1. Almost 52 percent of the strikes occurred at altitudes of less
than 100 feet, and 26.7 percent occurred between 101 and 1000 feet.
2. Eighty-five percent of the strikes occurred at airspeeds of 150
knots or less.
3. Where bird types were reported, 27.6 percent of the strikes
involved small birds and 58.6 involved medium size birds (2 pounds or
less).
4. Incidents where the airplane was damaged showed that 16.9
percent resulted from small bird strikes and 64 percent resulted from
medium size bird strikes.
These data show that most bird strikes occur at takeoff and landing
altitudes and airspeeds, and that birds weighing two pounds or less are
struck most often. The standards of the proposed provision are based on
these statistics. Few fatalities and injuries resulted from the bird
strikes reported in the ICAO data. Similarly, a review of NTSB accident
records between 1982 and 1992 revealed no U.S. accidents resulting from
bird strikes to the windshields of commuter category airplanes. As a
result, the FAA is not able to illustrate the justification of this
provision on the basis of historical accidents. Instead, the standards
are being proposed based on the expert recommendations of the ARAC. It
is also noted that this standard will be applied in JAA member
countries and that U.S. manufacturers wishing to export to those
countries would be required to meet the standard in any event.
Given that this provision cannot be quantitatively supported on the
basis of past accidents alone, the FAA expressly requests public input
and comments on its expected costs and potential benefits.

Section 23.783 Doors

Proposed new paragraph (f) would require that the locks on lavatory
doors, if installed, be designed so that they would not trap occupants.
Lavatory door locks used in transport category airplanes (see
Sec. 25.783) meet the requirements of this proposed rule. The FAA
estimates that the incremental cost of this provision would be no more
than $25 per lock. The proposal would reduce the likelihood that
occupants would be trapped in a locked lavatory, both in emergency and
non-emergency situations.

Section 23.787 Baggage and Cargo Compartments

The proposed rule would extend to normal, utility, and acrobatic
airplanes the existing commuter requirement to prevent baggage from
hazardous shifting. The FAA estimates that an aerospace engineer would
be required for 1 hour, at a burdened cost of $60 per hour, to analyze
the subject loads that would need to be constrained. Tiedowns would
cost approximately $50 per baggage compartment, or no more than $100
per airplane. These additional costs would apply only to normal,
utility, or acrobatic airplanes since commuter category airplanes are
already subject to the requirement under the existing rule.
The potential benefits of the proposed provision include the
reduced likelihood: (1) That baggage compartments would be overloaded,
(2) that stowed baggage would shift dangerously, and (3) that essential
co-located equipment or wiring would be damaged.

Section 23.791 Passenger Information Signs

This proposed new section would require at least one illuminated
sign notifying all passengers when seat belts should be fastened. The
requirement would apply only to airplanes where flightcrew members
could not observe occupant seats or where the flightcrew compartment is
separated from the passenger compartment. The signs would have to be
legible to all seated passengers and be operable from a crewmember
station.
The FAA estimates that an aerospace engineer could design the
required sign(s) in 1 hour, at a burdened rate of $60 per hour. The
sign would cost approximately $200 per airplane, including parts and
installation costs. Maintenance costs for bulb replacement would be
negligible. The weight penalty associated with the light system would
also be minor (no more than 2 pounds).
The safety benefits of the proposed change would derive from the
increased likelihood that passengers would know when their seat belts
should be fastened.

Section 23.807 Emergency Exits

Proposed new Sec. 23.807(a)(4) would provide the same hazard
protection for a person using an emergency exit as that provided by
proposed Sec. 23.783(b) for a person who uses a passenger door.
Emergency exits could not be located with respect to a propeller disk
or any other hazard in a manner that would endanger persons using that
exit.
The FAA holds that no incremental cost would be incurred to meet
the standards of the proposed provision for newly certificated
airplanes. However, this notice specifically requests that interested
parties submit comments on the potential costs and methods of
compliance that manufacturers would choose to comply with this proposed
requirement.
The proposed revision to Sec. 23.807(b)(5) would editorially revise
the current egress requirements for acrobatic airplanes. New
Sec. 23.807(b)(6) would establish similar egress standards for utility
category airplanes that are certificated for spinning. Industry sources
estimate that an aerobatic, quick-release door would cost an
incremental $10,000 in engineering design per affected airplane model
and an additional $500 per production airplane. Little or no additional
weight is expected. These costs would apply only in cases where the
manufacturer determines that the marketplace return of a combination
type certificate would outweigh the additional costs of design and
production.

Section 23.841 Pressurized Cabins

The proposed revision to Sec. 23.841(a) would extend the cabin
pressure requirements of current paragraph (a), which now apply to
airplanes certificated for operation above 31,000 feet, to airplanes
certificated for operation above 25,000 feet. Current part 25, JAR 25,
and proposed JAR 23 include the same requirement proposed here. This
proposed requirement is intended to protect airplane occupants from
harm if a malfunction occurs at altitudes where symptoms of hypoxia
occur, usually above 25,000 feet.
For airplanes that will be certificated for maximum altitude
operation between 25,000 feet and 31,000 feet, the proposal would
necessitate two additional pressure altitude regulators and associated
plumbing. Industry sources estimate that the proposed requirement would
cost an incremental $1,000 in engineering design per affected airplane
model and $2,000 per production airplane. Any additional weight would
be negligible.
The benefits of the proposal would derive from the incremental
protection against hypoxia afforded to occupants of airplanes
certificated for maximum altitude between 25,000 and 31,000 feet. Due
to the increasing use of turbine engines, more part 23 airplanes are
likely to be approved for operation above 25,000 feet. In the absence
of this proposed rule, an increasing number of occupants would be
exposed to the potential for harm in the event of a failure or
malfunction of the pressure system on these airplanes.

Section 23.855 Cargo and Baggage Compartment Fire Protection

Proposed paragraph (a) would require all sources of heat within
each cargo and baggage compartment that are capable of igniting the
compartment contents to be shielded and insulated to prevent such
ignition. Existing Sec. 23.787(f) requires that cargo compartment lamps
be installed so as to prevent contact between the lamp bulb and cargo.
The proposal would clarify and extend this provision to include all
sources of heat for baggage as well as cargo compartments.
Lights and (rarely) heaters for pets are typically the only sources
of heat located in a baggage or cargo compartment. A wire cage, costing
no more than $20, around the heat source would meet these requirements.
The FAA estimates that the cost of compliance per airplane would be no
more than $40 in those rare cases where such protection would not have
been provided anyway. The benefit of the proposed provision is a
reduction in the possibility of fire caused by the ignition of
compartment contents by lights or heaters.
Proposed paragraph (b) would require cargo and baggage compartments
to be constructed of materials that meet the appropriate provisions of
Sec. 23.853(d)(3). Currently these requirements apply to commuter
category airplanes and to the materials used in the compartments of
these airplanes. The proposed new requirement would expand this
applicability to the cargo and baggage compartments of all part 23
airplanes. In effect, the proposed new requirement would require
materials that are self-extinguishing rather than flame resistant as
currently required under Sec. 23.787(d).
Information provided by manufacturers shows that materials that
meet self-extinguishing flame requirements are available at a slightly
higher cost than materials that meet flame resistant requirements. The
FAA conservatively estimates that the incremental costs of complying
with proposed Sec. 23.855(b) would be less than $200 per airplane. The
safety benefits of this provision would be an increase in cargo and
baggage compartment fire protection.
Proposed new paragraph (c) would add new fire protection
requirements for cargo and baggage compartments for commuter category
airplanes. The proposed rule would require one of the following three
alternatives:
(1) The compartment just be located where pilots seated at their
duty station would easily discover the fire or the compartment must be
equipped with a smoke or fire detector system to warn the pilot's
station. The compartment must also be accessible for fire extinguisher
application.
(2) The compartment may be inaccessible, but must be equipped with
a fire detector system that warns the pilot station, and the
compartment must have ceiling and sidewall floor panels constructed of
materials that have been subjected to and meet the vertical self-
extinguishing tests of appendix F to part 23.
(3) The compartment must be constructed and sealed to contain any
fire.
The FAA cannot predict the designs of cargo and baggage compartment
for future airplanes. If manufacturers choose to use smoke detectors,
however, no more than 2 smoke detectors would be required per airplane.
An aerospace engineer could determine the most appropriate location and
design the smoke detector system in approximately 30 hours at a
burdened rate of $60 per hour, for a total cost of $1,800 per
certification. Two detectors, including wiring and installation, are
estimated to cost about $4,550. Maintenance costs for the smoke
detectors would cost approximately $100 per year. Materials that would
meet the vertical self-extinguishing tests of appendix F (see option 2
in the discussion above) would result in incremental costs of less than
$200 per airplane.
The FAA estimates that it would cost $500 to construct a sealed
compartment, or a total of $1,000 for 2 compartments, if the
manufacturer chooses that method of complying with the proposed
requirement (see option 3 in the discussion above).
Irrespective of the individual compliance method, the benefits of
the proposed provision would come from the increased likelihood that a
cargo or baggage compartment fire would either be extinguished or
contained.

Section 23.1303 Flight and Navigation Instruments

Revised Sec. 23.1303(d) would add the requirement for a free air
temperature indicator for those airplanes whose performance must be
based on weight, altitude, and temperature. This requirement already
applies to turbine powered airplanes. The proposal would extend the
requirement to reciprocating engine powered airplanes of more than
6,000 pounds. Industry sources estimate that the proposed requirement
would cost an incremental $500 in engineering design per affected
airplane model and $350 per production airplane. Any additional weight
would be negligible. The potential benefits of the proposal would
accrue from the requirement that the information necessary to determine
the performance envelope of the airplane be available to the pilot.
Proposed Sec. 23.1303(g) would identify specific instruments, and
limits of those instruments, required for commuter category airplanes.
Proposed Sec. 23.1303(g)(1) states that if airspeed limitations vary
with altitude, the airspeed indicators must show the variation of the
maximum operating limit speed (VMO) with altitude. Industry
sources indicate that an airspeed indicator with VMO ``pointer''
would cost $1,000 more than one without. Two airspeed indicators are
required on commuter airplanes, therefore, the incremental cost of this
requirement would be $2,000 per commuter category airplane produced.
The potential safety benefit of the proposal would derive from the
requirement that the information necessary to determine the maximum
operating limit speed be available at all altitudes.
Proposed Sec. 23.1303(g)(3) would require (for commuter category
IFR-approved airplanes with passenger seating configurations of 10
more) a third, independent, attitude indicator (AI). Industry sources
estimate that an aerospace engineer could design and document a third
attitude instrument system in 100 hours at a burdened rate of $60 per
hour, totalling $6,000 per certification. It is estimated that an AI
would cost approximately $8,000, including a standby battery, and that
the installation would cost $2,200 for 40 hours of a mechanic's time at
a burdened rate of $55 per hour. However, proposed Sec. 23.1311(a)(5),
discussed below, would delete the requirement for a rate-of-turn
indicator when an independent attitude indicator is installed. The
costs associated with a rate-of-turn indicator include: 40 hours of
design and documentation costs, $1,000 per indicator, and 40 hours of
installation. Therefore, the incremental cost for an IFR-approved
airplane with a passenger seating capacity of 10 or more would be
$3,600 for 60 hours of engineering (100 hours for the AI, minus 40
hours for the rate-of-turn indicator); $7,000 for the instrument
($8,000 for the AI, minus $1,000 for the rate-of-turn indicator); and
no additional cost for the installation (40 hours for the AI, minus 40
hours for the rate-of-turn indicator).
The potential safety benefits of a third, independent attitude
indicator would derive from the reduced potential for erroneous
attitude information. Currently, two attitude instruments are required
for a ten passenger, IFR approved commuter category airplane. Service
experience has shown that a failure can occur whereby an attitude
indicator can appear to be working when it is actually providing
incorrect information. During such a failure, pilots may have
difficulty determining which instrument to follow, and hazardous flight
attitudes may result. A third attitude indicator would allow the crew
to retain reliable attitude information even in cases where one
instrument is not operating correctly.

Section 23. 1326 Pitot Heat Indication System

Proposed new G23.1326 would require the installation of a pitot
tube heat indicating system on those airplanes required to be equipped
with a heated pitot tube. Heated pitot tubes ensure that moisture will
not freeze in the tube and block or partially block the airspeed
system.
A pitot heat indicating system, including an in-line current
sensor, panel light, and associated wiring, would cost approximately
$500. According to industry sources, an aerospace engineer could design
and document such a system in 20 hours at a burdened rate of $60 per
hour, totalling $1,200. A mechanic could install the system in 20 hours
at a burden rate of $55 per hour, totalling $1,100. The estimated non-
recurring cost per certification, therefore, would total $2,800 ($1,200
for design, $500 for the certification airplane's indicator, and $1,100
for installation of that indicator). The estimated cost per production
airplane would be $1,600 ($500 for the system and $1,100 for
installation).
The National Transportation Safety Board (NTSB) investigated a
series of single model accidents that occurred between May 1989 and
March 1991. During that period, five fatal accidents and a near fatal
incident occurred in the United States. Two additional fatal accidents
involving the same airplane model occurred in foreign countries. The
NTSB's analysis indicated that four of the five U.S. accidents probably
involved ice blockage of the pitot tubes because the pilots failed to
activate pitot heat before flying into freezing instrument
meteorological conditions. The Board recommended (A-92-86) that the FAA
consider requiring a pitot heat operating light on small airplanes
certificated to operate in icing conditions.
A pitot heat indicating system would advise the pilots of any
inoperative heating element in the pitot tube and that subsequent
inaccuracies could result. The proposed provision would reduce the
likelihood that pilots would rely on inaccurate airspeed information
resulting from a blocked or partially blocked pitot tube.

Section 23.1353 Storage Battery Design and Installation

Section 23.1359 Electrical System Fire Protection.

Proposed Sec. 23.1359(c) would provide burn criteria for electrical
wire and cables. A proposed revision to appendix F to part 23 would add
appropriate wire testing criteria. Demonstrating and documenting that
electrical wires and cables meet the requirements of this provision
would take an aerospace engineer approximately 4 hours at a burdened
rate of $60 per hour, for a total of $240 per certification. The
requirement and testing criteria would increase the likelihood that
necessary wires and cables would continue to function in the event of a
fire.

Section 23.1365 Electrical Cables and Equipment

Proposed Sec. 23.1365(d) would add a requirement for the
identification of electrical cables, terminals, and connectors.
Different colored wires and/or tags could be used in conjunction with a
wiring diagram to identify the cables, terminals, and connectors. The
FAA estimates that a draftsman could design and document this
identification system in 80 hours at a burdened rate of $55 per hour, a
total of $4,400 per certification. Incremental installation costs would
be approximately $100 per airplane.
The increasing use of electrical systems in part 23 airplanes has
added to the difficultly of wiring installation. The proposed
requirement for cable identification would increase the likelihood that
cables would be correctly installed initially and would be correctly
reinstalled as part of later maintenance or modification.

Section 23.1401 Anticollision Light System

The proposal would revise Sec. 23.1401 to require the installation
of an anticollision light system on all part 23 airplanes. Current
Sec. 23.1401 requires an anticollision light system only if
certification for night operations is requested. Many manufacturers
currently install anticollision light systems on all airplanes they
produce.
Industry sources estimate that an aerospace engineer could design
and document an anticollision light system in 40 hours at a burdened
rate of $60 per hour, for a total of $2,400 per affected certification.
The system would cost $500 and would take a mechanic approximately 20
hours to install at a burdened rate of $55 per hour, a total of $1,600
per affected airplane ($500 + (20 hours x $55 per hour) = $1,600).
The weight penalty would be negligible. Only those future models that
would not otherwise have anticollision light systems would actually
incur incremental costs as a result of this provision.
The number of airplanes that have been added to the small airplane
fleet and the increasing speeds resulting from improved technology,
especially turbine engines, warrant the use of anticollision lights for
day operations as well as night. The FAA Accident and Incident data for
the period 1984 through 1990 show that 269 aircraft were involved in
midair collisions in which 108 fatalities occurred. When the data were
filtered (to account for night operations, IFR conditions, and aircraft
not affected by this proposal), it shows that at least 167 airplanes
were involved in accidents or incidents that occurred in day VFR
conditions. The reports do not reveal whether the airplanes were using
anticollision lights at the time of the accident.
The FAA holds that requiring the installation of anticollision
lights on all newly certificated airplanes, and requiring their
operation during day operations (as proposed by revised Sec. 91.209 and
discussed later in this evaluation), would reduce the number of
daylight, midair accidents. Even if the proposed requirement were only
25 percent effective, the 6-year accident history indicates that
approximately 17 fatalities could be avoided during a similar 6-year
period.

Section 23.1431 Electronic Equipment

This proposal would add three new paragraphs to Sec. 23.1431.
Proposed new paragraph (c) would require that airplanes required to be
operated by more than one flightcrew member must be evaluated to
determine if the flightcrew members can converse without difficulty
when they are seated at their duty stations. If the required evaluation
shows that the noise level does not impair conversation, no further
action would be required. If the evaluation shows that conversation
would be difficult, however, an intercommunication system would be
required.
The FAA estimates that an evaluation of cockpit noise could be
conducted in conjunction with other certification testing, therefore,
no incremental costs are associated with the evaluation. An aerospace
engineer could design an intercom system in 20 hours at a burdened rate
of $60 per hour, for a total of $1,200 per affected certification. The
FAA estimates that the addition of an intercom system would cost
approximately $500 per airplane. A mechanic could install the system in
approximately 20 hours at a burdened rate or $55 per hour. The total
incremental production cost for an affected airplane, therefore, would
be $1,600 ($500 + 20 hours x $55 per hour)).
Proposed new paragraph (d) would require that if the communication
equipment that is installed includes any means of switching from the
receive mode to the transmit mode, the equipment must use ``off-on''
transmitter switching that turns the transmitter off when it is not
being used. The cost of this feature is included in the $500 cost of
the intercom, described above.
NTSB investigation of at least two commuter accidents determined
that excessive cockpit noise levels probably adversely affected the
ability of the flight crews to communicate (Bar Harbor Airlines, Flight
1808, August 25, 1985, 8 fatalities; and Henson Airlines, Flight 1517,
September 23, 1985, 14 fatalities.)
As a result, the Board recommended (A-86-113) that the FAA require
the installation and use of crew interphone systems in the cockpit of
airplanes operating under part 135. The benefit of the proposed
requirement would derive from the increased likelihood that flightcrew
members would be able to converse without difficulty and that the
safety hazard of miscommunication would be reduced.

Section 23.1447 Equipment Standards for Oxygen Dispensing Units

Proposed new Sec. 23.1447(a)(4) would require that if radio
equipment is installed in an airplane, flightcrew oxygen dispensing
units must be designed to allow use of the communication equipment when
oxygen is being used.
Industry sources estimate that an oxygen mask with an integral
microphone costs $1,000 more than an oxygen mask without a microphone.
The costs per affected airplane, therefore, would be $2,000 for two
masks. The benefit of the proposed requirement is that it would allow
flightcrew communication under all operating conditions, including
operations when oxygen is required.

Section 23.1453 Protection of Oxygen Equipment From Rupture

This proposed new section would clarify the rupture protection
needed for oxygen system installation. Rupture protection for oxygen
systems is currently required by the application of the structures load
requirements of part 23. The addition of Sec. 23.1453(a) would clarify
the application of these load requirements and would identify the need
to consider maximum temperatures and pressures that may be present.
Section 23.1453(b) would identify the protection to be provided for
high pressure oxygen sources and the high pressure lines that connect
these sources to the oxygen system shutoff valves.
Industry sources estimate that an aerospace engineer could analyze
and document the loads on each element of the oxygen system in 16 hours
at a burdened rate of $60 per hour, for a total cost of $960. The
routing of oxygen pressure sources and lines to protect them from
unsafe temperatures and crash landings would be part of an airplane's
basic design and would not impose incremental costs.

Section 91.209 Aircraft Lights

Proposed new Sec. 91.209(b) would require airplanes equipped with
an anticollision light system to operate those lights during all
operations, including daytime VFR.
The incremental cost of this provision would be incurred for light
bulb replacement. The FAA estimates that a light bulb for an
anticollision light system costs approximately $50 and that this
provision would necessitate an incremental bulb replacement every two
years. Accordingly, the cost is projected to equal $25 per year, per
affected operating airplane.
In summary, the FAA holds that the benefits of the proposed rule,
though not directly quantifiable, would exceed the expected costs.

Regulatory Flexibility Determination

The Regulator Flexibility Act of 1980 (RFA) was enacted by Congress
to ensure that small entities are not unnecessarily or
disproportionately burdened by Government regulations. The RFA requires
a Regulatory Flexibility Analysis if a proposed rule would have a
significant economic impact, either detrimental or beneficial, on a
substantial number of small entities. FAA Order 2100.14A, Regulatory
Flexibility Criteria and Guidance, establishes threshold cost values
and small entity size standards for complying with RFA review
requirements in FAA rulemaking actions. The proposed amendments would
not have a significant economic impact on a substantial number of small
entities.

Trade Impact Assessment

The proposed rule would not constitute a barrier to international
trade, including the export of American goods and services to foreign
countries and the import of foreign goods and services into the United
States. Instead, the proposed systems airworthiness standards would be
harmonized with those of foreign aviation authorities and would lessen
the restraints on trade.

Federalism Implications

The regulations proposed herein would not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.

Conclusion

The FAA proposes to revise the airworthiness standards to provide
systems and equipment standards for normal, utility, acrobatic, and
commuter airplanes that are the same as the standards that will be
proposed for the same category airplanes by the Joint Aviation
Authorities in Europe. If adopted, the proposed revision would reduce
the regulatory burden on the United States and European airplane
manufacturers by relieving them on the need to show compliance with
different standards each time they seek certification approval of an
airplane in a different country.
For the reasons discussed in the preamble, and based on the
findings in the Regulatory Evaluation, the FAA has determined that this
proposed regulation is not significant under Executive Order 12866. In
addition, the FAA certifies that this proposal, if adopted, will not
have a significant economic impact, positive or negative, on a
substantial number of small entities under the criteria of the
Regulatory Flexibility Act. This proposal is not considered significant
under DOT Regulatory Policies and Procedures (44 FR 11034, February 26,
1979). An initial regulatory evaluation of the proposal has been placed
in the docket. A copy may be obtained by contacting the person
identified under FOR FURTHER INFORMATION CONTACT:

List of Subjects

14 CFR Part 23

Aircraft, Aviation safety, Signs and symbols.

14 CFR Part 91

Agriculture, Aircraft, Airmen, Airports, Air traffic control,
Aviation safety, Canada, Cuba, Freight, Mexico, Noise control,
Political candidates, Reporting and recordkeeping requirements, Safety,
Smoking.

The Proposed Amendment

In consideration of the foregoing, the Federal Aviation
Administration proposes to amend parts 23 and 91 of the Federal
Aviation Regulations (14 CFR part 23 and 91) as follows:

PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND
COMMUTER CATEGORY AIRPLANES

1. The authority citation for part 23 continues to read as follows:

Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1425,
1428, 1429, 1430; 49 U.S.C. 106(g).

2. Section 23.677 is amended by revising paragraph (a) to read as
follows:

Sec. 23.677 Trim systems.

(a) Proper precautions must be taken to prevent inadvertent,
improper, or abrupt trim tab operation. There must be means near the
trim control to indicate to the pilot the direction of trim control
movement relative to airplane motion. In addition, there must be means
to indicate to the pilot the position of the trim device with respect
to both the range of adjustment and, in the case of lateral and
directional trim, the neutral position. This means must be visible to
the pilot and must be located and designed to prevent confusion. The
pitch trim indicator must be clearly marked with a position or range
within which it has been demonstrated that take-off is safe for all
center or gravity positions and each flap position approved for
takeoff.
* * * * *
3. A new Sec. 23.691 is added to read as follows:

Sec. 23.691 Artificial stall barrier system.

If the function of an artificial stall barrier, for example, stick
pusher, is necessary to show compliance with Sec. 23.201(c), the system
must comply with the following:
(a) With the system adjusted for operation, the plus and minus
airspeeds at which downward pitching control will be provided must be
established.
(b) Considering the plus and minus airspeed tolerances established
by paragraph (a) of this section, and airspeed must be selected for the
activation of the downward pitching control that provides a safe margin
above any airspeed at which any unsatisfactory stall characteristics
occur.
(c) In addition to the stall warning required by Sec. 23.207, a
warning that is clearly distinguishable to the pilot under all expected
flight conditions without requiring the pilot's attention, must be
provided for faults that would prevent the system from providing the
required pitching motion.
(d) Each system must be designed so that the artificial stall
barrier can be quickly and positively disengaged by the pilots to
prevent unwanted downward pitching of the airplane by a quick release
(emergency) control that meets the requirements of Sec. 23.1329(b).
(e) A preflight check of the complete system must be established
and the procedure for this check made available in the Airplane Flight
Manual (AFM). Preflight checks that are critical to the safety of the
airplane must be included in the limitations section of the AFM.
(f) For those airplanes whose design includes an autopilot system:
(1) A quick release (emergency) control installed in accordance
with Sec. 23.1329(b) may be used to meet the requirements of paragraph
(d) of this section, and
(2) The pitch servo for that system may be used to provide the
stall downward pitching motion.
(g) In showing compliance with Sec. 23.1309, the system must be
evaluated to determine the effect that any announced or unannounced
failure may have on the continued safe flight and landing of the
airplane or the ability of the crew to cope with any adverse conditions
that may result from such failures. This evaluation must consider the
hazards that would result from the airplane's flight characteristics if
the system was not provided, and the hazard that may result from
unwanted downward pitching motion, which could result from failures at
airspeeds above the selected stall speed.
4. Section 23.697 is amended by adding a new paragraph (c) to read
as follows:

Sec. 23.697 Wing flap controls.

* * * * *
(c) If compliance with Sec. 23.145(b)(3) necessitates wing flap
retraction to positions that are not fully retracted, the wing flap
control lever settings corresponding to those positions must be
positively located such that a definite change of direction of movement
of the lever is necessary to select settings beyond those settings.
5. Section 23.701 is amended by revising paragraphs (a)(1) and
(a)(2) to read as follows:

Sec. 23.701 Flap interconnection.

(a) * * *
(1) Be synchronized by a mechanical interconnection between the
movable flap surfaces that is independent of the flap drive system; or
by an approved equivalent means; or
(2) Be designed so that the occurrence of any failure of the flap
system that would result in an unsafe flight characteristic of the
airplane is extremely improbable; or
* * * * *
6. A new Sec. 23.703 is added to read as follows:

Sec. 23.703 Takeoff warning system.

For commuter category airplanes, unless it can be shown that a lift
or longitudinal trim device which affects the takeoff performance of
the aircraft would not give an unsafe takeoff configuration when
selected out of an approved takeoff position, a takeoff warning system
must be installed and meet the following requirements:
(a) The system must provide to the pilots an aural warning that is
automatically activated during the initial portion of the takeoff roll
if the airplane is in a configuration that would not allow a safe
takeoff. The warning must continue until--
(1) The configuration is changed to allow safe takeoff, or
(2) Action is taken by the pilot to abandon the takeoff roll.
(b) The means used to activate the system must function properly
for all authorized takeoff power settings and procedures and throughout
the ranges of takeoff weights, altitudes and temperatures for which
certification is requested.

Sec. 23.723 [Amended]

7. Section 23.723(b) is amended by changing the word ``reserved''
to ``reserve''.
8. Section 23.729 is amended by revising paragraph (e) and by
adding a new paragraph (g) to read as follows:

Sec. 23.729 Landing gear extension and retraction system.

* * * * *
(e) Position indicator. If a retractable landing gear is used,
there must be a landing gear position indicator (as well as necessary
switches to actuate the indicator) or other means to inform the pilot
that each gear is secured in the extended (or retracted) position. If
switches are used, they must be located and coupled to the landing gear
mechanical system in a manner that prevents an erroneous indication of
either ``down and locked'' if each gear is not in the fully extended
position, or of ``up and locked'' if each landing gear is not in the
fully retracted position.
* * * * *
(g) Equipment located in the landing gear bay. If the landing gear
bay is used as the location for equipment other than the landing gear,
that equipment must be designed and installed to minimize damage.

9. Section 23.735 is amended by redesignating paragraph (c) as
paragraph (d), by revising the introductory text of paragraph (a), and
by adding new paragraphs (c) and (e) to read as follows:

Sec. 23.735 Brakes.

(a) Brakes must be provided. The landing brake kinetic energy
capacity rating of each main wheel brake assembly must not be less than
the kinetic energy absorption requirements determined under either of
the following methods:
* * * * *
(c) During the landing distance determination required by
Sec. 23.75, the pressure on the wheel braking system must not exceed
the pressure specified by the brake manufacturer.
* * * * *
(e) In addition, for commuter category airplanes, the rejected
takeoff brake kinetic energy capacity rating of each main wheel brake
assembly must not be less than the kinetic energy absorption
requirements determined under either of the following methods--
(1) The brake kinetic energy absorption requirements must be based
on a conservative rational analysis of the sequence of events expected
during a rejected takeoff at the design takeoff weight.
(2) Instead of a rational analysis, the kinetic energy absorption
requirements for each main wheel brake assembly may be derived from the
following formula--

KE=0.0443 WV\2\/N
where,
KE=Kinetic energy per wheel (ft.-lbs.);
W=Design takeoff weight (lbs.);
V=Ground speed associated with the maximum value of V1 selected in
accordance with Sec. 23.51(c)(1);
N=Number of main wheels with brakes.

10. A new Sec. 23.745 is added to read as follows:

Sec. 23.745 Nose/tail wheel steering.

(a) If nose/tail wheel steering is installed, it must be
demonstrated that its use does not require exceptional pilot skill
during takeoff and landing, in crosswinds and in the event of an engine
failure; or its use must be limited to low speed maneuvering.
(b) Movement of the pilot's steering control must not interfere
with the retraction or extension of the landing gear.

11. Section 23.775 is amended by revising paragraphs (a) and (c),
by redesignating paragraph (d) as (e) and paragraph (e) as (d), by
revising the newly designated paragraph (e), and by adding a new
paragraph (h) to read as follows:

Sec. 23.775 Windshields and windows.

(a) The internal panels of windshields and windows must be
constructed of a nonsplintering material, such as nonsplintering safety
glass.
* * * * *
(c) On pressurized airplanes, if certification for operation up to
and including 25,000 feet is requested, an enclosure canopy including a
representative part of the installation must be subjected to special
tests to account for the combined effects of continuous and cyclic
pressurization loadings and flight loads, or compliance with the fail-
safe requirements of paragraph (d) of this section must be shown.
* * * * *
(e) The windshield and side windows forward of the pilot's back
when the pilot is seated in the normal flight position must have a
luminous transmittance value of not less than 70 percent.
* * * * *
(h) In addition, for commuter category airplanes, the following
applies:
(1) Windshield panes directly in front of the pilots in the normal
conduct of their duties, and the supporting structures for these panes
must withstand, without penetration, the impact of a two-pound bird
when the velocity of the airplane (relative to the bird along the
airplane's flight path) is equal to the airplane's maximum approach
flap speed.
(2) The windshield panels in front of the pilots must be arranged
so that, assuming the loss of vision through any one panel, one or more
panels remain available for use by a pilot seated at a pilot station to
permit continued safe flight and landing.
12. Section 23.783 is amended by revising paragraph (b) and by
adding a new paragraph (g) to read as follows:

Sec. 23.783 Doors.

* * * * *
(b) Passenger doors must not be located with respect to any
propeller disk or any other potential hazard so as to endanger persons
using that door.
* * * * *
(g) If lavatory doors are installed, they must be designed to
preclude an occupant from becoming trapped inside the lavatory. If a
locking mechanism is installed, it must be capable of being unlocked
from outside of the lavatory.
13. Section 23.785 is amended by adding introductory text and by
revising paragraph (b) to read as follows:

Sec. 23.785 Seats, berths, litters, safety belts and shoulder
harnesses.

There must be a seat or berth for each occupant that meets the
following:
* * * * *
(b) Each forward-facing or aft-facing seat/restraint system in
normal, utility, or acrobatic category airplanes must consist of a
seat, a safety belt, and a shoulder harness, with a metal-to-metal
latching device as required by Sec. 23.1413, that are designed to
provide the occupant protection provisions required in Sec. 23.562.
Other seat orientations must provide the same level of occupant
protection as a forward-facing or aft-facing seat with a safety belt
and a shoulder harness, and must provide the protection provisions of
Sec. 23.562.
* * * * *
14. Section 23.787 is revised to read as follows:

Sec. 23.787 Baggage and cargo compartments.

(a) Each baggage and cargo compartment must:
(1) Be designed for its placarded maximum weight of contents and
for the critical load distributions at the appropriate maximum load
factors corresponding to the flight and ground load conditions of this
part.
(2) Have means to prevent the contents of any compartment from
becoming a hazard by shifting, and to protect any controls, wiring,
lines, equipment or accessories whose damage or failure would affect
safe operations.
(3) Have a means to protect occupants from injury by the contents
of any compartment, located aft of the occupants and separated by
structure, when the ultimate forward inertial load factor is 9g and
assuming the maximum allowed baggage or cargo weight for the
compartment.
(b) Designs that provide for baggage or cargo to be carried in the
same compartment as passengers must have a means to protect the
occupants from injury when the baggage or cargo is subjected to the
inertial loads resulting from the ultimate static load factors of
Sec. 23.561(b)(3), assuming the maximum allowed baggage or cargo weight
for the compartment.
(c) For airplanes that are used only for the carriage of cargo, the
flightcrew emergency exits must meet the requirements of Sec. 23.807
under any cargo loading conditions.

15. A new Sec. 23.791 is added to read as follows:

Sec. 23.791 Passenger information signs.

For those airplanes in which the flightcrew members cannot observe
the other occupants' seats or where the flightcrew members' compartment
is separated from the passenger compartment, there must be at least one
illuminated sign (using either letters or symbols) notifying all
passengers when seat belts should be fastened. Signs that notify when
seat belts should be fastened must:
(a) When illuminated, be legible to each person seated in the
passenger compartment under all probable lighting conditions; and
(b) Be installed so that a flightcrew member can, when seated at
the flightcrew member's station, turn the illumination on and off.

16. Section 23.807 is amended by revising paragraphs (b)
introductory text and (b)(5) and by adding new paragraphs (a)(4) and
(b)(6) to read as follows:

Sec. 23.807 Emergency exits.

(a) * * *
(4) Emergency exits must not be located with respect to any
propeller disk or any other potential hazard so as to endanger persons
using that exit.
(b) Type and operation. Emergency exits must be movable windows,
panels, canopies, or external doors, openable from both inside and
outside the airplane, that provide a clear and unobstructed opening
large enough to admit a 19-by-26-inch ellipse. Auxiliary locking
devices used to secure the airplane must be designed to be overridden
by the normal internal opening means. The inside handles of emergency
exits that open outward must be adequately protected against
inadvertent operation. In addition, each emergency exit must--
* * * * *
(5) In the case of acrobatic category airplanes, allow each
occupant to abandon the airplane at any speed between VSO and
VD; and
(6) In the case of utility category airplanes certificated for
spinning, allow each occupant to abandon the airplane at the highest
speed likely to be achieved in the maneuver for which the airplane is
certificated.
* * * * *

Sec. 23.841 [Amended]

17. Section 23.841 is amended in paragraph (a) by removing the
number ``31,000'' and replacing it with ``25,000''.
18. Section 23.853 is amended by revising the section heading to
read as follows:

Sec. 23.853 Passenger and crew compartment interiors.

* * * * *
19. A new Sec. 23.855 is added to read as follows:

Sec. 23.855 Cargo and baggage compartment fire protection.

(a) Sources of heat within each cargo and baggage compartment that
are capable of igniting the compartment contents must be shielded and
insulated to prevent such ignition.
(b) Each cargo and baggage compartment must be constructed of
materials that meet the appropriate provisions of Sec. 23.853(d)(3).
(c) In addition for commuter category airplanes, each cargo and
baggage compartment must:
(1) Be located where the presence of a fire would be easily
discovered by the pilots when seated at their duty station, or it must
be equipped with a smoke or fire detector system to give a warning at
the pilots' station, and provide sufficient access to enable a pilot to
effectively reach any part of the compartment with the contents of a
hand held fire extinguisher, or
(2) Be equipped with a smoke or fire detector system to give a
warning at the pilots' station and have ceiling and sidewall liners and
floor panels constructed of materials that have been subjected to and
meet the 45 degree angle test of Appendix F of this part. The flame may
not penetrate (pass through) the material during application of the
flame or subsequent to its removal. The average flame time after
removal of the flame source may not exceed 15 seconds, and the average
glow time may not exceed 10 seconds. The compartment must be
constructed to provide fire protection that is not less than that
required of its individual panels; or
(3) Be constructed and sealed to contain any fire within the
compartment.

20. Section 23.867 is amended by revising the heading that precedes
the section and the section heading to read as follows:

Electrical Bonding and Lightning Protection

Sec. 23.867 Electrical bonding and protection against lightning and
static electricity.

* * * * *
21. Section 23.1303 is amended by revising the introductory text;
by amending paragraph (d) by inserting the words ``reciprocating
engine-powered airplanes of more than 6,000 pounds maximum weight and''
between the words ``For'' and ``turbine''; by amending paragraph (e)
concluding text by adding a line to read, ``The lower limit of the
warning device must be set to minimize nuisance warning;'' at the end
of the paragraph and by adding new paragraphs (f) and (g) to read as
follows:

Sec. 23.1303 Flight and navigation instruments.

The following are the minimum required flight and navigation
instruments:
* * * * *
(f) When an attitude display is installed, the instrument design
must not provide any means, accessible to the flightcrew, of adjusting
the relative positions of the attitude reference symbol and the horizon
line beyond that necessary for parallax correction.
(g) In addition, for commuter category air planes:
(1) If airspeed limitations vary with altitude, the airspeed
indicator must have a maximum allowable airspeed indicator showing the
variation of VMO with altitude.
(2) The altimeter must be a sensitive type.
(3) Having a passenger seating configuration of 10 or more,
excluding the pilot's seats and that are approved for IFR operations, a
third attitude instrument must be provided that:
(i) Is powered from a source independent of the electrical
generating system;
(ii) Continues reliable operation for a minimum of 30 minutes after
total failure of the electrical generating system;
(iii) Operates independently of any other attitude indicating
system;
(iv) Is operative without selection after total failure of the
electrical generating system;
(v) Is located on the instrument panel in a position acceptable to
the Administrator that will make it plainly visible to and usable by
any pilot at the pilot's station; and
(vi) Is appropriately lighted during all phases of operation.

Sec. 23.1307 [Amended]

22. Section 23.1307 is amended by removing paragraphs (a) and (b);
and by removing the designation from paragraph (c).
23. Section 23.1309 is amended by adding a new paragraph (a)(4) to
read as follows:

Sec. 23.1309 Equipment, systems, and installations.

(a) * * *
(4) In a commuter category airplane, must be designed to safeguard
against hazards to the airplane in the event of their malfunction or
failure.
* * * * *
24. Section 23.1311 is revised to read as follows:

Sec. 23.1311 Electronic display instrument systems.

(a) Electronic display indicators, including those with features
that make isolation and independence between powerplant instrument
systems impractical, must:
(1) Meet the arrangement and visibility requirements of
Sec. 23.1321.
(2) Be easily legible under all lighting conditions encountered in
the cockpit, including direct sunlight, considering the expected
electronic display brightness level at the end of an electronic display
indicator's useful life. Specific limitations on display system useful
life must be contained in the Instructions for Continued Airworthiness
required by Sec. 23.1529.
(3) Not inhibit the primary display of attitude, airspeed,
altitude, or powerplant parameters needed by any pilot to set power
within established limitations, in any normal mode of operation.
(4) Not inhibit the primary display of engine parameters needed by
any pilot to properly set or monitor powerplant limitations during the
engine starting mode of operation.
(5) Have an independent magnetic direction indicator and either an
independent secondary mechanical altimeter, airspeed indicator, and
attitude instrument or individual electronic display indicators for the
altimeter, airspeed, and attitude indicator that are independent from
the airplane's primary electrical power system. These secondary
instruments may be installed in panel positions that are displaced from
the primary positions specified by Sec. 23.1321(d), but must be located
where they meet the pilots' visibility requirements of Sec. 23.1321(a).
(6) Incorporate sensory cues for the pilot that are equivalent to
those in the instrument being replaced by the electronic display
indicators.
(7) Incorporate visual displays of instrument markings, required by
Secs. 23.1541 through 23.1553, or visual displays that alert the pilot
to abnormal operational values or approaches to established limitation
values, for each parameter required to be displayed by this part.
(b) The electronic display indicators, including their systems and
installations, and considering other airplane systems, must be designed
so that one display of information essential for continued safe flight
and landing will remain available to the crew, without need for
immediate action by any pilot for continued safe operation, after any
single failure or probable combination of failures.
(c) As used in this section, ``instrument'' includes devices that
are physically contained in one unit, and devices that are composed of
two or more physically separate units or components connected together
(such as a remote indicating gyroscopic direction indicator that
includes a magnetic sensing element, a gyroscopic unit, an amplifier,
and an indicator connected together). As used in this section,
``primary'' display refers to the display of a parameter that is
located in the instrument panel such that the pilot looks at it first
when wanting to view that parameter.

Sec. 23.1321 [Amended]

25. Section 23.1321 is amended by removing the words ``certificated
for flight under instrument flight rules or of more than 6,000 pounds
maximum weight'' from paragraph (d) introductory test.
26. Section 23.1323 is amended by redesignating paragraph (c) as
(e); by removing paragraph (d); by redesignating paragraph (e) as new
paragraph (d); by removing the words ``in flight and'' from the first
sentence of redesignated paragraph (e); and by adding new paragraphs
(c) and (f) to read as follows:

Sec. 23.1323 Airspeed indicating system.

* * * * *
(c) The design and installation of each airspeed indicating system
must provide positive drainage of moisture from the pitot static
plumbing.
* * * * *
(f) For commuter category airplanes, where duplicate airspeed
indicators are required, their respective pitot tubes must be far
enough apart to avoid damage to both tubes in a collision with a bird.

Sec. 23.1325 [Amended]

27. Section 23.1325 is amended by inserting the words ``or icing''
between the words ``meteorological'' and ``conditions'' in paragraph
(g).
28. A new Sec. 23.1326 is added to read as follows:

Sec. 23.1326 Pitot heat indication systems.

If a flight instrument pitot heating system is installed to meet
the requirements specified in Sec. 23.1323(d), an indication system
must be provided to indicate to the flight crew when that pitot heating
system is not operating. The indication system must comply with the
following requirements:
(a) The indication provided must incorporate an amber light that is
in clear view of a flightcrew member.
(b) The indication provided must be designed to alert the flight
crew if either of the following conditions exist:
(1) The pitot heating system is switched ``off''.
(2) The pitot heating system is switched ``on'' and any pitot tube
heating element is inoperative.

Sec. 23.1329 [Amended]

29. Section 23.1329(b) is amended by adding the parenthetical
phrase ``(both stick controls, if the airplane can be operated from
either pilot seat)'' between the words, ``or on the stick control,''
and the word ``such''.
30. Section 23.1337 is amended by revising the section heading, by
revising the introductory text of paragraph (b), by redesignating
paragraphs (b)(4) and (b)(5) as paragraph (b)(5) and (b)(6),
respectively, and by adding a new paragraph (b)(4) to read as follows:

Sec. 23.1337 Powerplant instruments installation.

* * * * *
(b) Fuel quantity indication. There must be a means to indicate to
the flightcrew members the quantity of usable fuel in each tank during
flight. An indicator calibrated in appropriate units and clearly marked
to indicate those units must be used. In addition:
* * * * *
(4) There must be a means to indicate the amount of usable fuel in
each tank when the airplane is on the ground (such as by a stick
gauge);
* * * * *
31. Section 23.1351 is amended by removing paragraph (b)(4), by
redesignating paragraphs (b)(5) as (b)(4), by adding a sentence to the
end of paragraph (f) that reads, ``The external power connection must
be located so that its use will not result in a hazard to the airplane
or ground personnel'', and by revisiting paragraphs (b)(2), (b)(3), and
(c)(3) to read as follows:

Sec. 23.1351 General.

* * * * *
(b) * * *
(2) Electric power source must function properly when connected in
combination or independently.
(3) No failure or malfunction of any electric power source may
impair the ability of any remaining source to supply load circuits
essential for safe operation.
* * * * *
(c) * * *
(3) Automatic means must be provided to prevent either damage to
any generator/alternator or adverse effects on the airplane electrical
system due to reverse current. A means must also be provided to
disconnect each generator/alternator from the battery and other
generators/alternators.
* * * * *
32. Section 23.1353 is amended by adding a new paragraph (h) to
read as follows:

Sec. 23.1353 Storage battery design and installation.

* * * * *
(h) In the event of a complete loss of the primary electrical power
generating system, the battery must be capable of providing at least 30
minutes of electrical power to those loads that are essential to
continue safe flight and landing. The 30 minute time period includes
the time needed for the pilots to recognize the loss of generated power
and take appropriate load shedding action.
33. A new Sec. 23.1359 is added to read as follows:

Sec. 23.1359 Electrical system fire protection.

(a) Each component of the electrical system must meet the
applicable fire protection requirement of Secs. 23.863 and 23.1182.
(b) Electrical cables, terminals, and equipment in designated fire
zones that are used during emergency procedures must be fire-resistant.
(c) Insulation on electrical wire and electrical cable must be
self-extinguishing when tested at an angle of 60 degrees in accordance
with the applicable portions of Appendix F of this part, or other
approved equivalent methods. The average burn length must not exceed 3
inches (76 mm) and the average flame time after removal of the flame
source must not exceed 30 seconds. Drippings from the test specimen
must not continue to flame for more than an average of 3 seconds after
falling.

Sec. 23.1361 [Amended]

34. Section 23.1361(c) is amended by removing the last two words
``in flight''.
35. Section 23.1365 is amended by revising paragraph (b) and by
adding new paragraphs (d), (e), and (f) to read as follows:

Sec. 23.1365 Electrical cables and equipment.

* * * * *
(b) Any equipment that is associated with any electrical cable
installation and that would overheat in the event of circuit overload
or fault must be flame resistant. The equipment and the electrical
cables must not emit dangerous quantities of toxic fumes.
* * * * *
(d) Means of identification must be provided for electrical cables,
terminals, and connectors.
(e) Electrical cables must be installed such that the risk of
mechanical damage and/or damage caused by fluids, vapors, or sources of
heat, is minimized.
(f) Where a cable cannot be protected by a circuit protection
device or other overload protection, it must not cause a fire hazard
under fault conditions.
36. Section 23.1383 is revised to read as follows:

Sec. 23.1383 Taxi and landing lights.

Each taxi and landing light must be designed and installed so that:
(a) No dangerous glare is visible to the pilots.
(b) The pilot is not seriously affected by halation.
(c) It provides enough light for night operations.
(d) It does not cause a fire hazard in any configuration.
37. Section 23.1401 is amended by revising the introductory text of
paragraph (a) to read as follows:

Sec. 23.1401 Anticollision light system.

(a) General. The airplane must have an anticollision light system
that:
* * * * *
38. Section 23.1431 is amended by adding new paragraphs (c), (d),
and (e) to read as follows:

Sec. 23.1431 Electronic equipment.

* * * * *
(c) For those airplanes required to have more than one flightcrew
member, or whose operation will require more than one flightcrew
member, the cockpit must be evaluated to determine if the flightcrew
members, when seated at their duty station, can converse without
difficulty. If the airplane design includes provision for the use of
communication headsets, the evaluation must also consider conditions
where headsets are being used. If the evaluation shows conditions under
which it will be difficult to converse, an intercommunication system
must be provided.
(d) If installed communication equipment includes transmitter
``off-on'' switching, that switching means must be designed to return
from the ``transmit'' to the ``off'' position when it is released and
ensure that the transmitter will return to the off (non transmitting)
state.
(e) If provisions for the use of communication headsets are
provided, it must be demonstrated that the flightcrew members will
receive all aural warnings when any headset is being used.
39. Section 23.1435 is amended by revising paragraph (c) to read as
follows:

Sec. 23.1435 Hydraulic systems.

* * * * *
(c) Accumulators. A hydraulic accumulator or reservoir may be
installed on the engine side of any firewall if--
(1) It is an integral part of an engine or propeller system, or
(2) The reservoir is nonpressurized and the total capacity of all
such nonpressurized reservoirs is one quart or less.
40. Section 23.1447 is amended by revising paragraphs (d) and (e)
and by adding a new paragraph (a)(4) to read as follows:

Sec. 23.1447 Equipment standards for oxygen dispensing units.

* * * * *
(a) * * *
(4) If radio equipment is installed, the flightcrew oxygen
dispensing units must be designed to allow the use of that equipment
and to allow communication with any other required crew member while at
their assigned duty station.
* * * * *
(d) For a pressurized airplane designed to operate at flight
altitudes above 25,000 feet (MSL), the dispensing units must meet the
following:
(1) The dispensing units for passengers must be connected to an
oxygen supply terminal and be immediately available to each occupant
wherever seated.
(2) The dispensing units for crewmembers must be automatically
presented to each crewmember before the cabin pressure altitude exceeds
15,000 feet, or the units must be of the quick-donning type, connected
to an oxygen supply terminal that is immediately available to
crewmembers at their station.
(e) If certification for operation above 30,000 feet is requested,
the dispensing units for passengers must be automatically presented to
each occupant before the cabin pressure altitude exceeds 15,000 feet.
* * * * *
41. A new Sec. 23.1451 is added to read as follows:

Sec. 23.1451 Fire protection for oxygen equipment.

Oxygen equipment and lines must:
(a) Not be installed in any designated fire zones.
(b) Be protected from heat that may be generated in, or escape
from, any designated fire zone.
(c) Be installed so that escaping oxygen cannot come in contact
with and cause ignition of grease, fluid, or vapor accumulations that
are present in normal operation or that may result from the failure or
malfunction of any other system.
42. A new Sec. 23.1453 is added to read as follows:

Sec. 23.1453 Protection of oxygen equipment from rupture.

(a) Each element of the oxygen system must have sufficient strength
to withstand the maximum pressure and temperature, in combination with
any externally applied loads arising from consideration of limit
structural loads, that may be acting on that part of the system.
(b) High pressure oxygen sources and the lines between the source
and the shutoff means must be:
(1) Protected from unsafe temperatures; and
(2) Located where the probability and hazard of rupture in a crash
landing are minimized.
43. Section 23.1461 is amended by revising paragraph (a) to read as
follows:

Sec. 23.1461 Equipment containing high energy rotors.

(a) Equipment, such as Auxiliary Power Units (APU) and constant
speed drive units, containing high energy rotors must meet paragraphs
(b), (c), or (d) of this section.
* * * * *
44. Appendix F to part 23 is amended by revising the introductory
paragraph, by amending paragraph (c) to change the reference from
paragraph (e) to paragraph (g), by amending paragraph (d) to change the
reference from paragraph (f) to paragraph (h), by redesignating current
paragraph (f) as paragraph (h), and by revising paragraph (b) and
adding new paragraphs (f) and (g) to read as follows:

Appendix F to Part 23--Test Procedure

An acceptable test procedure for self-extinguishing materials for
showing compliance with Secs. 23.853, 23.855 and 23.1359.
* * * * *
(b) Specimen configuration. Except as provided for materials used
in electrical wire and cable insulation and in small parts, materials
must be tested either as a section cut from a fabricated part as
installed in the airplane or as a specimen simulating a cut section,
such as: a specimen cut from a flat sheet of the material or a model of
the fabricated part. The specimen may be cut from any location in a
fabricated part; however, fabricated units, such as sandwich panels,
may not be separated for a test. The specimen thickness must be no
thicker than the minimum thickness to be qualified for use in the
airplane, except that: (1) Thick foam parts, such as seat cushions,
must be tested in \1/2\-inch thickness; (2) when showing compliance
with Sec. 23.853(d)(3)(v) for materials used in small parts that must
be tested, the materials must be tested in no more than \1/8\-inch
thickness; (3) when showing compliance with Sec. 23.1359(c) for
materials used in electrical wire and cable insulation, the wire and
cable specimens must be the same size as used in the airplane. In the
case of fabrics, both the warp and fill direction of the weave must be
tested to determine the most critical flammability conditions. When
performing the tests prescribed in paragraphs (d) and (e) of this
appendix, the specimen must be mounted in a metal frame so that (1) in
the vertical tests of paragraph (d) of this appendix, the two long
edges and the upper edge are held securely; (2) in the horizontal test
of paragraph (e) of this appendix, the two long edges and the edge away
from the flame are held securely; (3) the exposed area of the specimen
is at least 2 inches wide and 12 inches long, unless the actual size
used in the airplane is smaller; and (4) the edge to which the burner
flame is applied must not consist of the finished or protected edge of
the specimen but must be representative of the actual cross section of
the material or part installed in the airplane. When performing the
test prescribed in paragraph (f) of this appendix, the specimen must be
mounted in a metal frame so that all four edges are held securely and
the exposed area of the specimen is at least 8 inches by 8 inches.
* * * * *
(f) Forty-five degree test. A minimum of three specimens must be
tested and the results averaged. The specimens must be supported at an
angle of 45 degrees to a horizontal surface. The exposed surface when
installed in the aircraft must be face down for the test. The specimens
must be exposed to a Bunsen or Tirrill burner with a nominal \3/8\-inch
I.D. tube adjusted to give a flame of 1\1/2\ inches in height. The
minimum flame temperature measured by a calibrated thermocouple
pyrometer in the center of the flame must be 1550 deg.F. Suitable
precautions must be taken to avoid drafts. The flame must be applied
for 30 seconds with one-third contacting the material at the center of
the specimen and then removed. Flame time, glow time, and whether the
flame penetrates (passes through) the specimen must be recorded.
(g) Sixty-degree test. A minimum of three specimens of each wire
specification (make and size) must be tested. The specimen of wire or
cable (including insulation) must be placed at an angle of 60 degrees
with the horizontal in the cabinet specified in paragraph (c) of this
appendix, with the cabinet door open during the test or placed within a
chamber approximately 2 feet high x 1 foot x 1 foot, open at the top
and at one vertical side (front), that allows sufficient flow of air
for complete combustion but is free from drafts. The specimen must be
parallel to and approximately 6 inches from the front of the chamber.
The lower end of the specimen must be held rigidly clamped. The upper
end of the specimen must pass over a pulley or rod and must have an
appropriate weight attached to it so that the specimen is held tautly
throughout the flammability test. The test specimen span between lower
clamp and upper pulley or rod must be 24 inches and must be marked 8
inches from the lower end to indicate the central point for flame
application. A flame from a Bunsen or Tirrill burner must be applied
for 30 seconds at the test mark. The burner must be mounted underneath
the test mark on the specimen, perpendicular to the specimen and at an
angle of 30 degrees to the vertical plane of the specimen. The burner
must have a nominal bore of three-eighths inch, and must be adjusted to
provide a three-inch-high flame with an inner cone approximately one-
third of the flame height. The minimum temperature of the hottest
portion of the flame, as measured with a calibrated thermocouple
pyrometer, may not be less than 1,750 deg.F. The burner must be
positioned so that the hottest portion of the flame is applied to the
test mark on the wire. Flame time, burn length, and flaming time of
drippings, if any, must be recorded. The burn length determined in
accordance with paragraph (h) of this appendix must be measured to the
nearest one-tenth inch. Breaking of the wire specimen is not considered
a failure.
* * * * *

PART 91--GENERAL OPERATING AND FLIGHT RULES

45. The authority citation for part 91 continues to read as
follows:

Authority: 49 U.S.C. 1301(7), 1303, 1344, 1348, 1352 through
1355, 1401, 1421 through 1431, 1471, 1472, 1502, 1510, 1522, and
2121 through 2125; Articles 12, 29, 21, and 32(a) of the Convention
on International Civil Aviation (61 Stat. 1180); 42 U.S.C. 4321 et
seq.; E.O. 11514; 49 U.S.C. 106(g).

46. Section 91.205 is amended by redesignating paragraphs (b)(11)
through (b)(16) as paragraphs (b)(12) through (b)(17), respectively,
and by adding a new paragraph (b)(11) to read as follows:

Sec. 91.205 Powered civil aircraft with standard category U.S.
airworthiness certificates: Instrument and equipment requirements.

* * * * *
(b) * * *
(11) For small civil airplanes certificated after [INSERT DATE OF
THIS AMENDMENT], in accordance with part 23, as amended by amendment
23-[INSERT AMENDMENT NUMBER], an approved aviation red or aviation
white anticollision light system. In the event of failure of any light
of the anticollision light system, operation of the aircraft may
continue to a location where repairs or replacement can be made.
* * * * *

47. Section 91.209 is revised to read as follows:

Sec. 91.209 Aircraft lights.

No person may:
(a) During the period from sunset to sunrise (or, in Alaska, during
the period a prominent unlighted object cannot be seen from a distance
of 3 statute miles or the sun is more than 6 degrees below the
horizon)--
(1) Operate an aircraft unless it has lighted position lights;
(2) Park or move an aircraft in, or in dangerous proximity to, a
night flight operations area of an airport unless the aircraft--
(i) Is clearly illuminated;
(ii) Has lighted position lights; or
(iii) Is in an area that is marked by obstruction lights;
(3) Anchor an aircraft unless the aircraft--
(i) Has lighted anchor lights; or
(ii) Is in an area where anchor lights are not required on vessels;
or
(b) Operate an aircraft that is equipped with an anticollision
light system, unless it has lighted anticollision lights. However, the
anticollision lights need not be lighted when the pilot-in-command
determines that, because of operating conditions, it would be in the
interest of safety to turn the lights off.

Issued in Washington DC on July 14, 1994.
Thomas E. McSweeny,
Director, Aircraft Certification Service.
[FR Doc. 94-17798 Filed 7-21-94; 8:45 am]
BILLING CODE 4910-13-M