[Federal Register Volume 59, Number 141 (Monday, July 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17994]
[[Page Unknown]]
[Federal Register: July 25, 1994]
_______________________________________________________________________
Part IV
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
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14 CFR Parts 1 and 23
Airworthiness Standards; Flight Proposals Based on European Joint
Aviation Requirements Proposals; Proposed Rule
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 1 and 23
[Docket No. 27807; Notice No. 94-22]
RIN 2120-AE61
Airworthiness Standards; Flight Proposals Based on European Joint
Aviation Requirements Proposals
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking.
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SUMMARY: This document proposed changes to the flight 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 flight 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)
simplifying airworthiness approvals for import and export purposes.
DATES: Comments must be submitted on or before November 22, 1994.
ADDRESSES: Comments on this notice should be mailed in triplicate to:
Federal Aviation Administration, Office of the Chief Counsel,
Attention: Rules Docket (AGC-200), Docket No. 27807, 800 Independence
Avenue, SW., Washington, DC 20591. Comments delivered must be marked
Docket No. 27807. Comments may be inspected in Room 915G weekdays
between 8:30 a.m. and 5:00 p.m., except on Federal holidays.
In addition, the FAA is maintaining a duplicate 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
4:00 p.m.
FOR FURTHER INFORMATION CONTACT: Lowell Foster, ACE-111, 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. 27807.'' The postcard will be date
stamped and returned to the commenter.
Availability of NPRM
Any person may obtain a copy of this Notice of Proposed Rulemaking
(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 Europeenne 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 flight 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 23/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's disposition of the rulemaking issues
coordinated between the JAA and the FAA. The draft NPRM's 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/FAR 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 flight 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 throroughly 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 1.1 General Definitions
This proposal would amend Sec. 1.1 to add a definition of ``maximum
speed for stability characteristics, VFC/MFC.'' This proposed
change would harmonize part 1 and JAR 1. The definition is currently
contained in Sec. 23.175(b)(2) and also in Sec. 25.253(b). Moving the
definition to part 1 would simplify the text of part 23 and ease the
referencing of the term VFC/MFC. The definition would be
deleted from Sec. 23.175(b)(2).
Section 23.3 Airplane Categories
This proposal would make a change to the limited aerobatic
operations authorized for utility category certification, change the
authorized commuter category certification maneuvers and prohibit dual
type certification of commuter category airplanes.
The limitation for utility category airplanes in Sec. 23.3(b)(2)
would be revised to add an outside limit of 90 degrees in angle of bank
for lazy eights, chandelles, and steep turns.
Section 23.3(d) would be revised to delete chandelles and lazy
eights as approved operations in commuter category airplanes because
the FAA does not anticipate any operational need for such maneuvers.
Further, Sec. 23.3(e) would be revised to prohibit type
certification of commuter category airplanes in any other category. In
the preamble discussion of Proposal 3 for Amendment No. 23-34 (52 FR
1806, January 15, 1987), the FAA discussed the issue of dual
certification, with emphasis on the issuance of airworthiness
certificates. Since then, the FAA has gained experience with airplanes
certificated in both normal and commuter categories. The FAA has found
confusion among pilots and operators about the appropriate performance
limitations.
Although the proposed performance requirements, based on weight,
altitude, and temperature (WAT) criteria (see proposal for Sec. 23.45),
would alleviate some of the problems with current airplanes, the FAA
proposes that commuter category airplanes not have dual type
certificates. One problem with dual type certification is pilot
confusion. WAT limits would differ between normal and commuter
categories, requiring pilots who get type rated in these airplanes to
know two sets of limitations and to remember when each set of
limitations is applicable. This proposed rule would not preclude the
type certification of similar airplanes with different model numbers,
such as the present Cessna models 500 and 501.
Section 23.25 Weight Limits
This proposal would make changes to Sec. 23.25(a) and remove
references to commuter category zero fuel weight in paragraph (a) and
standby power rocket engines in paragraph (a)(1)(iii).
Revised Sec. 23.25(a) would clarify that the maximum weight that
must be selected is the least of the three choices given in
Sec. 23.25(a)(1). The airframe NPRM proposes moving the commuter
category zero fuel weight requirement in Sec. 23.25(a) to Sec. 23.343.
The FAA proposes removing the reference to both standby power rocket
engines and to appendix E in Sec. 23.25(a)(1)(iii) because this is a
rare and obsolete design feature. If standby power rocket engines were
proposed as a design feature, the FAA would issue special conditions to
ensure adequate airworthiness.
Section 23.33 Propeller Speed and Pitch Limits
Proposed revisions to Sec. 23.33(b)(1) would delete the reference
to Vy and replace it with ``the all engine(s) operating climb
speed specified in Sec. 23.65.'' This would be done for consistency
with other changes in performance requirements. Section 23.33(b)(2)
would be revised to use ``VNE'' in place of ``never exceed
speed,'' since VNE is defined in part 1, and to delete the world
``placarded'' which is unnecessary.
Section 23.45 General
In Notice of Proposed Rulemaking, Small Airplane Airworthiness
Review Program Notice No. 4, Notice No. 90-18 (55 FR 26534, June 28,
1990), the FAA requested comments on the need for weight, altitude, and
temperature (WAT) criteria, as information or as a limitation on
piston-powered, twin-engine part 23 airplanes. The FAA also requested
comments about WAT criteria on turbine-powered twin-engine part 23
airplanes, specifically during takeoff and landing.
WAT criteria is used to determine the maximum weight an airplane
can have in relation to altitude and temperature for safe takeoff. This
criteria provides a pilot with the information needed to determine if a
takeoff and climb can be successfully completed, including for
multiengine airplanes, if one engine becomes inoperative. WAT criteria
has been required under part 23 for commuter category airplanes, at all
approved altitudes. A limited WAT criteria has been required for
turbine engine powered airplanes at 5,000 feet and at standard
temperatures plus 40 deg.F, but not for higher altitudes or
temperatures. For some multiengine powered airplanes WAT data has been
provided by the manufacturer as information to pilots but is not
required to be followed.
The FAA received three comments on mandating WAT criteria in part
23. One commenter (GAMA) ``believes that WAT information is useful but
certainly not the only way to present operating data for any airplane''
and that making WAT criteria an airplane or operating limitation for
part 23 airplanes is ``an unnecessary and unjustified expansion or
redirection of operating criteria.''
Another commenter (the Airline Pilots Associaton--ALPA) wants WAT
information furnished during the certification process. The commenter
cites the variety of operational uses of these airplanes including in
scheduled air carrier and regional airline service. The commenter also
cities the need for ``one level'' of safety as justification for
expanding the WAT requirements.
The other commenter (JAA) also supports WAT criteria. This
commenter believes that the chance of a single-engine failure on any
airplane is high. Also, this commenter warns that safety considerations
include airplane occupants and personnel on the ground. According to
the commenter, transport category airplanes follow WAT criteria by
limiting the operation of the airplane. Beyond the point where takeoff
can be rejected, one-engine-inoperative climbs must guarantee obstacle
clearance. The commenter recognizes a need for generally similar
requirements for commuter category airplanes.
The JAA believes that requiring a continued flight capability would
preclude the operation of single-engine airplanes. Also, the commenter
believes that airplane size and stall speed provide characteristics
that permit safe landings in the event of an inoperative engine for
single-engine airplanes and smaller multiengine airplanes.
The commenter points out that between the two extremes of the
transport category airplane and the single-engine airplane lies the
light twin-engine reciprocating airplanes and turbine engine airplanes,
ranging from four seats to nine and from 4,000 to 12,500 pounds. The
commenter notes that, for these types of airplanes, it would be
burdensome to require compliance with full net flight path obstacle
clearance. In the commenter's opinion, a safe forced landing becomes
less satisfactory with increased takeoff weight, involving longer
stopping distances even for the same landing speed. The commenter notes
that the twin-engine airplanes have other significant adverse
characteristics compared to single-engine airplanes. First, an engine
failure is twice as probable; second, asymmetric power demands
immediate pilot action.
The commenter also points out that the inability to continue flight
with one engine inoperative creates the following situation: the chance
of a second engine failure is increased; a suitable site for an
emergency landing is reduced; and the pilot resists the inevitable
forced landing and tries to maintain flight. Training under more
favorable conditions may have taught the pilot to expect success in
those situations. In unfavorable conditions, attempts to maintain
flight may lead to loss of airspeed at high asymmetric power and,
commonly, loss of directional control that results in a stall/spin
accident.
The commenter advocates certification and operating criteria for
multiengine airplanes that blend the performance requirements for a
single-engine airplane and a transport category airplane. The commenter
believes that the existing requirements accept a limited period of risk
just before and just after liftoff, where engine failure may not be
fully accounted for. The commenter believes that the application of WAT
limits clearly accounts for actual conditions, although the climb
gradient requirements are lower than the requirements of part 25/JAR
25.
The commenter proposes no distinction between reciprocating and
turbine engines. In the commenter's opinion, the WAT criteria should be
imposed, where applicable, as limitations through the Airplane Flight
Manual (AFM).
The commenter does not believe that such proposals would involve
costs disproportionate to the benefit. The commenter suggests that the
comment from the Small Airplane Airworthiness Review Conference, held
October 22-26, 1984, that such criteria would ``eliminate the
certification of an entire class of airplanes,'' is an exaggeration.
The proposals are achievable, in the commenter's view, by typical
modern light twin-engine airplanes with realistic payloads,
particularly the more significant executive/air taxi airplanes. The
adoption of the WAT concept, in the commenter's opinion, would instill
a greater awareness of performance consideration in pilots from an
early stage of their training.
The commenter also believes that the requirements on climb and
handling qualities of the present Secs. 23.65 and 23.67 are illogical
and unreasonable. The commenter recommends using WAT criteria so that
it applies equally to all airplane operations because it offers
improved airplane capability.
The commenter points out that manufacturers of ``WAT type''
airplanes routinely determine performance under a wide range of
conditions. The commenter also notes that flight manuals produced to
the widely accepted General Aviation Manufacturers Association (GAMA)
specification already contain performance data beyond the minimum
requirements of part 23. In the commenter's opinion, additional testing
or data scheduling create no additional costs.
To determine the necessity of applying WAT criteria to other than
transport and commuter airplanes, the commenter notes that present
draft JAR 23 applies WAT limits only to piston-engine airplanes above
6,000 pounds and turbine-engine airplanes. The JAR Operations Study
Group proposes applying WAT limits to all JAR 23 airplanes in
commercial operations.
In 1991, the FAA studied the accident record of reciprocating
engine-powered, multiengine part 23 airplanes of over 6,000 pounds
maximum takeoff weight with a substantial fleet size. The FAA completed
the study using the National Transportation Safety Board (NTSB)
accident briefs and evaluated those statistics over the study period of
the individual airplanes. The statistics show the following:
(a) Over 100 accidents and 200 fatalities occurred due to engine
failure during the study period.
(b) Forty-seven of the engine failure accidents occurred because
the pilot failed to maintain flying speed and/or directional control.
(c) Engine reliability is a significant factor in the accident
study. (For example, airplanes of similar or the same aerodynamic
configuration, but with different engines, have significantly different
accident records.)
After reviewing the accident statistics, and recognizing the
performance capabilities of the accident airplanes, the FAA concludes
the following:
(a) Engine reliability would not be of major concern if the
airplane had adequate performance on the remaining operative engine.
(b) The loss of flying speed and subsequent loss of airplane
control would not be a significant problem if the airplane exhibited
adequate climb performance capabilities to fly out of an engine loss
situation at low speeds.
Based on these statistics and conclusions from the FAA 1991 study
and on comments, the FAA has determined that WAT limits are necessary
for safe operation of multiengine airplanes of the type that will be
involved in transporting passengers for hire. Operating rules (part
135) are already in place that specify some performance limitations.
The cutoff weight for reciprocating engine-powered airplanes of 6,000
pounds would encompass most airplanes of concern. All turbine engine-
powered airplanes are included because of the adverse effect of
increasing temperatures on turbine engine performance.
This proposal would change Sec. 23.45 to require weight, altitude,
and temperature (WAT) performance accountability for normal, utility,
and acrobatic airplanes with a maximum takeoff weight over 6,000 pounds
and all turbine-powered airplanes. Including WAT accountability
necessitates reorganization and revisions to all paragraphs of this
section. The inclusion of WAT accountability in part 23 also requires
changes to several other sections in part 23.
Paragraph (a)(1) would be revised to require that performance
requirements be met for still air and ``standard atmosphere.'' Current
(a)(1) uses the term ``standard atmospheric conditions.''
The applicability of paragraph (a) (1) and (2) would be revised to
require that all airplanes meet the performance requirements in still
air and standard atmosphere, and that ambient atmospheric conditions,
which currently must be met by commuter category airplanes, would have
to be met by (1) commuter category airplanes, (2) reciprocating engine-
powered airplanes of more than 6,000 pounds maximum weight, and (3)
turbine engine-powered airplanes.
Proposed paragraph (b) would replace current requirements of
paragraph (b), pertaining to power or thrust available, with the
altitude and temperature requirements for performance data.
Proposed Sec. 23.45(c) is modified Sec. 23.51. It would require
that performance data be determined with the cowl flaps in the position
used in cooling tests required by Sec. 23.1041 to Sec. 23.1047 and
permits the cowl flap position to be addressed uniformly.
Proposed paragraph (d) is the same as current paragraph (c)
pertaining to the determination of available propulsion thrust.
Proposed changes to Sec. 23.45 (b), (c), (d), and (e) would delete
references to ``thrust'' and retain just ``power,'' for standardization
with the JAR. This is considered appropriate since power covers engine
output, despite how the absorbed power is transmitted to the
atmosphere. The FAA proposes this change in subsequent sections where
the term ``power or thrust'' is used.
Proposed paragraph (e) is the same as requirements of current
paragraph (d) with a minor editorial revision.
Proposed new paragraph (f) is based on current paragraphs (e)(3)
and (e)(5)(i), which apply only to commuter category airplanes.
Proposed changes to Sec. 23.45(f) would extend to all airplane
categories the requirement for all takeoff and landing procedures to be
consistently executable by pilots of average skill. This is considered
appropriate since takeoffs and landings must be made routinely by
operational pilots. It is also appropriate that takeoff and landing
performance data published in the Airplane Flight Manual (AFM) can be
consistently achieved by operational pilots.
Proposed new paragraph (g) would require determining takeoff
distance, accelerate-stop distance, takeoff distance and takeoff run,
and landing distance on a smooth, dry, hard-surfaced runway. The FAA
considers these limitations necessary for WAT limited airplanes since
the WAT takeoff performance is only valid on a particular defined
surface. The FAA does not consider the testing necessary to extend the
same limitations to non-WAT airplanes burdensome to applicants since
that information is already available in GAMA Spec. No. 1 AFM's.
Additionally, the proposal allows for the derivation of landing and
takeoff data on non-hard surfaces, such as grass and gravel and, thus,
may not require additional flight testing.
Proposed paragraph (h) is the same as current paragraph (e), which
covers additional performance requirements for commuter category
airplanes, except for some minor revisions. In the list of items to be
determined in paragraph (h)(3), ``landing distance'' would not be
included since it would already be covered in proposed Sec. 23.45(g). A
reference to Sec. 23.67 in paragraph (h)(4) would be updated to be
consistent with proposed revisions to that section in this notice; and
the phrase ``missed approaches'' would be changed to ``discontinued
approaches'' to be consistent with the proposed change to Sec. 23.143.
Proposed paragraph (h)(5)(i) requiring that the procedures must be able
to be consistently executed by a crew of average skill would have added
to it ``in atmospheric conditions reasonably expected to be encountered
in service.'' These clarifying words would also appear in paragraph
(h).
Section 23.49 Stalling Speed
Section 23.49 would be reorganized and edited for clarification.
Currently the requirements for VS0 and VS1 are separated with
parallel configuration items under paragraphs (a) and (d). The proposed
clarification would merge the VS0 and VS1 requirements under
paragraph (a). Existing paragraph (b) would be moved to paragraph (c)
and existing paragraph (c) would be moved to paragraph (d). Existing
paragraph (e) would become paragraph (b) and the thrust conditions in
paragraph (f) would be incorporated under paragraph (a) items (1) and
(2).
Proposed changes to paragraph (a) are as follows:
(1) Proposed paragraph (a)(4) would be a requirement that the
airplane be in the condition existing in the test, in which VS0
and VS1 are being used.
(2) Proposed paragraph (a)(5) would be a revised version of current
paragraph (a)(6). The current requirement states that the center of
gravity must be in the most unfavorable position within the allowable
landing range. The proposed requirement would state that the center of
gravity must be in the position that results in the highest value of
VS0 and VS1.
(3) As mentioned under Sec. 23.45, the current paragraph (a)(5)
would be moved to Sec. 23.45(c).
All of the changes are clarifying and not an increase in
requirements.
Section 23.51 Takeoff Speeds
This proposal would revise the paragraph heading from ``Takeoff''
to ``Takeoff speeds'' and incorporate the takeoff speed requirements
currently contained in Sec. 23.53. This revision to the heading and
reorganization of takeoff requirements is proposed for harmony with JAR
23.
Current Sec. 23.51(a) would be moved to Sec. 23.53(a). Current
paragraph (a) requires that the distance required to take off and climb
over a 50-foot obstacle must be determined with the engines operating
within approved operating limitations and with cowl flaps in the normal
takeoff position. These requirements as modified would be covered under
proposed Secs. 23.45 (c) and (d) and 23.1587.
Current Sec. 23.51(b) in measuring seaplane and amphibian takeoff
distances would be deleted because it is a statement of an acceptable
method of compliance. Also, there is not a need for addressing a
separate seaplane starting point.
Current Sec. 23.51(c) concerning pilot skills and conditions would
be deleted since it would be covered under the general requirements in
proposed Sec. 23.45(f).
Current Sec. 23.51(d) would be deleted because the requirements are
partly covered under Sec. 23.45 in commuter category performance and
other performance requirements. In addition, the information
requirements would be covered under Sec. 23.1587. Subpart G, under
which Sec. 23.1587 appears, is generally used to specify what
information must be in the AFM.
For multiengine normal, utility, and acrobatic category airplanes,
the determination of VR is transferred from Sec. 23.53(a) to
proposed Sec. 23.51(a) with minor changes in the specified rotation
speed. For multiengine airplanes, in proposed paragraph (a)(1), the
margin between rotation speed and VMC increases to 1.05 VMC,
or a margin of 1.10 VS1 is established between VR and stall.
Proposed paragraph (a) would define VR as the speed at which
the pilot makes a control input, with the intention of lifting the
airplane out of contact with the runway or water surface. This
definition would apply to tail wheel and tricycle gear airplanes,
seaplanes, and single-engine airplanes.
In addition to the multiengine rotation speed discussed above,
proposed paragraph (a) would include rotation speeds for single-engine
airplanes and seaplanes and amphibians. This proposed rule would extend
VR applicability to all part 23 airplanes to establish a safe and
standardized procedure that can be used by operational pilots to
achieve AFM takeoff performance. This proposed use of rotation speed is
consistent with part 25.
In proposed paragraph (b) the speed at 50 feet is based on current
Sec. 23.53(b) with no change in requirements.
For commuter category airplanes, the takeoff speed requirements
move from Sec. 23.53(c) to proposed Sec. 23.51(c) with editorial
changes. The option in proposed (c)(1)(i) for an applicant to determine
a VMCG and establish a V1 based on VMCG rather than a
margin above VMCA is added.
Section 23.53 Takeoff Performance
The heading of Sec. 23.53 would be new and the content would come
primarily from existing Sec. 23.51. This section would now provide
general takeoff performance requirements.
The proposal would move the takeoff speed requirements of the
current Sec. 23.53 to Sec. 23.51. (See proposal for Sec. 23.51.)
Proposed Sec. 23.53 provides general takeoff performance requirements
for normal, utility, acrobatic, and commuter category airplanes.
Proposed paragraph (a) is based on current Sec. 23.51(a). Proposed
paragraph (b) is a modification of current Sec. 23.1587(a)(5). Proposed
paragraph (c) is based on Sec. 23.51(d).
Section 23.55 Accelerate-stop Distance
This proposal would revise Sec. 23.55 to clarify the accelerate-
stop segments and to make editorial changes.
This proposal would divide the accelerate-stop maneuver into three
segments, rest to VEF (proposed (a)(1)), VEF to V1
(proposed (a)(2)), and V1 to rest (proposed (a)(3)). This is not a
new requirement, but it divides the total distance into three segments
to be considered. The phrase, ``in the case of engine failure,'' in
current Sec. 23.55(a)(2) would be deleted because it would be included
in proposed (a)(2). Also, the phrase, ``assuming that * * * the pilot
has decided to stop as indicated by application of the first retarding
means at the speed V1,'' is deleted because it is stated in
proposed Sec. 23.51(c)(1)(ii). The ``exceptional skill'' phrase of
Sec. 23.55(b)(3) would be deleted because it will remain in proposed
Sec. 23.45(h)(5)(i). The Sec. 23.55(b) phrase ``if that means is
available with the critical engine inoperative'' would be deleted
because it is covered by the safe and reliable requirements.
Section 23.57 Takeoff Path
Section 23.57 would be revised to clarify and specify which takeoff
path segments must be determined in flight. Proposed paragraph (a)
would clarify that the transition to the enroute configuration should
be completed on or before reaching 1500 feet above the takeoff surface.
In current Sec. 23.57(c)(1), the slope of the airborne part of the
takeoff path must be ``positive at each point''; this is changed in
proposed (c)(1) to ``not negative at any point,'' to allow acceleration
in level flight, which is implied by current Sec. 23.61(c). A proposed
editorial change to Sec. 23.57(c)(3) would specify that the climb
gradient ``must not be less than * * *,'' as opposed to ``may not be
less than. * * *'' The option in current Sec. 23.57(d) of determining
the takeoff path, either by continuous demonstration or by synthesis
from segments, no longer reflects current practice, nor is it entirely
desirable. The only viable option in determining the takeoff path from
rest to 35 feet above the takeoff surface is by a continuous
demonstration. The most practical method of determining the takeoff
path from 35 feet to 1500 feet above the takeoff surface is by
synthesis from segments. Accordingly, proposed Sec. 23.57(d) and (e)
would incorporate these changes.
Section 23.59 Takeoff Distance and Takeoff Run
This proposal would clarify Sec. 23.59 with no substantial change
in requirements. The proposal would change the opening text to clarify
that the determination of takeoff run is the applicant's option since
the applicant may choose not to present clearway data. The reference in
current Sec. 23.59(a)(2) and (b)(2) to ``along the takeoff path,'' in a
takeoff with all engines operating, would be deleted since takeoff path
is a one-engine-inoperative condition. Additionally, the reference to
VLOF is replaced with the words ``liftoff point'' to clarify that
the requirements specify a point and related distance, not a speed.
Section 23.63 Climbs: General
Proposed new Sec. 23.63 would assemble general climb requirements
from Secs. 23.65 and 23.67 into a single section and differentiate
between WAT limited airplanes (reciprocating engine powered airplanes
of above 6,000 pounds maximum takeoff weight and all turbine engine
powered airplanes) and those airplanes that are not WAT limited
(reciprocating engine powered airplanes of 6,000 pounds or less). (See
the proposed change to Sec. 23.45 for discussion of WAT limits.)
Proposed new Sec. 23.63(a)(1) would require that compliance be shown
out of ground effect. This requirement is in current Sec. 23.67(e),
which applies to commuter category airplanes. Proposed new
Sec. 23.63(a)(3) requires that compliance must be shown, unless
otherwise specified, with one engine inoperative, at a bank angle not
exceeding 5 degrees. This requirement is in current Sec. 23.149 and has
been applied generally for part 23 airplanes except commuter category
airplanes in certain circumstances.
Section 23.65 Climb: All Engines Operating
This proposal would clarify Sec. 23.65 and would change minimum
climb speeds for multiengine airplanes.
Proposed revisions to Sec. 23.65(a) would change the applicability
from ``each airplane'' as adopted in Amendment No. 23-45 (58 FR 42136,
August 6, 1993) to ``each normal, utility, and acrobatic category
reciprocating engine-powered airplane of 6,000 pounds or less maximum
weight.'' It would change the phrase ``angle of climb'' to ``climb
gradient'' and establish the climb gradient at 8.3 percent for
landplanes and 6.7 percent for seaplanes and amphibians with certain
specified performance conditions.
Proposed (a)(4) would establish a minimum climb speed for
multiengine airplanes of not less than the greater of 1.1 VMC and
1.2 VS1, which would provide a margin above VMC.
The cowl flap requirements currently in paragraph (a)(5) would be
moved to Sec. 23.45(c).
Current Sec. 23.65(b) would be deleted. These requirements should
have been deleted in Amendment No. 23-45 (58 FR 42136, August 6, 1993),
but they were overlooked. Since the adoption of Amendment No. 23-45
there is no longer a rate of climb requirement in Sec. 23.65(a). The
alternative means of compliance allowed by paragraph (b), therefore, is
obsolete and not consistent with the more stringent performance
requirements proposed by this NPRM. Also, the alternative means of
compliance in paragraph (b) was rarely used by applicants.
The proposed Sec. 23.65(b) would add WAT limits for reciprocating
engine-powered airplanes of more than 6,000 pounds maximum weight and
turbine engine-powered airplanes. (See proposal for Sec. 23.45 for
discussion of WAT limits.)
Current Sec. 23.65(c) would be moved to Sec. 23.65(b) and the
temperature and altitude requirements would be deleted since WAT limits
are proposed for turbine engine-powered airplanes and the four percent
gradient would apply at any approved takeoff ambient condition.
Proposed Sec. 23.65(b)(2) provides for landing gear down unless the
gear can be retracted in not more than seven seconds. This is more
stringent than the present requirement, but the same as the proposed
one-engine-inoperative takeoff climb requirements, and is considered
appropriate to this weight and class of airplane with WAT limits.
Current Sec. 23.65(d) would be deleted since the requirements would
be covered in the proposed Sec. 23.45(h)(2) and current Sec. 23.21.
Section 23.66 Takeoff Climb; One-engine Inoperative
Proposed new Sec. 23.66 would require the determination of the one-
engine-inoperative climb capacity of all WAT limited reciprocating
engine-powered and turbine engine-powered airplanes immediately after
takeoff. Since most reciprocating engine-powered airplanes do not have
autofeather, the condition immediately after takeoff can be critical.
There is not a minimum climb requirement in this configuration, only
the determination of the climb or descent gradient. This information
does not become a limitation; it is provided to the pilot in the AFM
(see Sec. 23.1587) to allow the pilot to make informed judgments before
takeoff.
Section 23.67 Climb: One Engine Inoperative
This proposal would reorganize Sec. 23.67 for harmonization with
the JAR; and would require WAT limits for some airplanes; require wings
level climb up to 400 feet for commuter category airplanes, and make
minor changes in airplane configuration requirements.
Revised Sec. 23.67(a) would specify the climb requirements for non-
WAT airplanes with no change in requirements for those airplanes.
Proposed Sec. 23.67(b) would specify climb requirements for WAT
airplanes. WAT criteria would be applied for both reciprocating engine-
powered airplanes of more than 6,000 pounds maximum weight and turbine
engine-powered airplanes. (See the discussion of WAT limits in the
proposed change to Sec. 23.45.) Turbine engine-powered airplanes are
currently subject to limited WAT limitations under Sec. 23.67(c), which
would be incorporated into proposed Sec. 23.67(b).
The takeoff flap position for normal, utility, and acrobatic
category reciprocating engine-powered airplanes of 6,000 pounds or less
is changed to ``wing flaps retracted'' from ``most favorable position''
(current Sec. 23.67(4)). Wing flaps retracted is the position most used
in certification and in service for this size of airplane. The proposed
change is contained in Sec. 23.67(a)(1)(iv), (a)(2)(iv), and
(b)(2)(iv).
Current Sec. 23.67(d) is deleted since all climb speeds (both all-
engine and one engine inoperative) are scheduled and the determination
of VY is no longer required. VY is also proposed to be
deleted in all other sections of part 23 for the same reason.
Current Sec. 23.67(e) for commuter category airplanes would be
redesignated as Sec. 23.67(c) with no change in requirements except
that the takeoff climb with landing gear extended must be conducted
with the landing gear doors open. This is a conservative approach
offered by the JAA to specify a definite gear door configuration and to
delete the requirement to determine performance during the transient
condition of gear doors opening and closing. Proposed Sec. 23.67(c)(1)
specifies that the first segment climb must be conducted with the wings
level and further specifies that the climb speed for the segment must
be V2 instead of the current requirement for a range of speeds
from VLOF and whatever the applicant selects at gear retraction.
Proposed Sec. 23.67(c)(2) requires conducting the second segment climb
with wings level, which would be appropriate for operational scenarios.
The current Sec. 23.67(e)(1) requirements are partially moved to
Sec. 23.67(c) and the remainder are contained in Sec. 23.63(a)(1) and
(d).
Proposed Sec. 23.67(c)(3), enroute climb, adds a minimum climb
speed to ensure an adequate margin above stall speed.
The proposed Sec. 23.67(c)(4) makes no substantive changes in the
current requirements of Sec. 23.67(e)(3) but does change the paragraph
heading from ``Approach'' to ``Discontinued approach.'' In addition,
proposed Sec. 23.67(c)(4) clarifies that the climb gradients must be
met at an altitude of 400 feet above the landing surface.
Section 23.69 Enroute Climb/Descent
Proposed new Sec. 23.69 would require the determination of all
engine and one-engine-inoperative climb/descent rates and gradients in
the enroute configuration under all operational WAT conditions. This
information is necessary for enroute flight planning and dispatch.
Climb speeds are specified to provide a margin above VSI.
Section 23.71 Glide: Single-engine Airplanes
Proposed new Sec. 23.71 would require the determination of glide
distance and speed for single-engine airplanes. The information is
necessary for flight planning and for providing the pilot with
information from which to make informed decisions.
Section 23.73 Reference Landing Approach Speed
Proposed new Sec. 23.73 would define the reference landing approach
speeds, VREF. Establishing a definition for these speeds
simplifies the use of VREF in other portions of the rule. The
VREF speeds for the various category airplanes are established as
not less than 1.3 V S0. Also, the established speeds consider the
appropriate relationship to VMC determined under Sec. 23.149.
Section 23.75 Landing Distance
This proposal would revise the heading, reorganize Sec. 23.75 for
harmonization with the JAR, add the landing reference speed, VREF,
and move the portion on brake pressures to Sec. 23.735, Brakes.
The introductory paragraph of this section would be revised to
delete the reference to the AFM because part 23, subpart B, is
generally used to specify what must be determined during flight test
and part 23, subpart G, is generally used to specify what must be
placed in the AFM. The introductory paragraph would also be revised to
require landing distances to be determined at standard temperature for
each weight and altitude. Service experience has shown that landing
distances are not sensitive to temperatures. The use of standard
temperature is consistent with WAT requirements and the increased level
of safety introduced in this NPRM. The revised introductory paragraph
deletes the reference to ``approximately 3 knots'' for seaplanes and
amphibians because this information will be moved to advisory material
on acceptable methods of compliance.
Revised Sec. 23.75(a) adds VREF and requires its use. (See
proposal for Sec. 23.73.)
The text of the current Sec. 23.75(b) is deleted because proposed
Sec. 23.45 would specify these general requirements. Proposed new
Sec. 23.75(b) clarifies that a constant configuration must be
maintained throughout the maneuver.
Revised Sec. 23.75(d) would continue the current requirement for
showing that a safe transition to the balked landing conditions can be
made and specify the weight that must be considered for the transition
to the balked landing conditions. This proposed new requirement
reflects current industry practice.
Proposed new Sec. 23.75(e) is a general requirement to ensure the
reliability of the brakes and tires.
Proposed Sec. 23.75(f) is revised by changing the first use of the
word ``means'' to ``retardation means,'' and by deleting paragraph
(f)(3). Paragraph (f)(3) requires that no more than average skill shall
be required to control the airplane. This topic is covered in proposed
Sec. 23.45(f).
Section Sec. 23.75(h) is deleted because the introductory paragraph
of proposed Sec. 23.75 would contain commuter category requirements and
proposed Sec. 23.1587 would require landing distance correction
factors.
Section 23.77 Balked Landing
This section would be revised to include additional WAT
requirements and to make editorial changes.
Proposed revisions to Sec. 23.77 (a) and (b) would differentiate
between WAT and non-WAT; and, in paragraph (b), would include the more
stringent WAT limited airplane requirements. (See proposal for
Sec. 23.45.) Section 23.77(a)(4) adds a new climb speed requirement to
ensure that acceleration is not required during the transition from
landing to balked landing. The climb gradient of Sec. 23.77(b) was
selected to be slightly less than the non-WAT airplane sea level
requirement as a tradeoff for a balked landing climb capability at all
altitudes and temperatures.
The commuter category climb gradient of 3.3 percent specified in
Sec. 23.77(c) changes to 3.2 percent for consistency with part 25.
Additional editorial changes and deletions are proposed for
Sec. 23.77(c) because the general requirements would be covered in the
proposed Sec. 23.45.
Section 23.143 General
Proposed Sec. 23.143(a) would be revised to add the phrase ``during
all flight phases'' to the lead-in of the paragraph. ``Go-around''
would be added to the list of flight phases.
The JAA/FAA decided, during FAR/JAR Harmonization meetings, that
the term ``go-around'' included the all engine balked landings of
Sec. 23.77, various all engine and one-engine-inoperative aborted
landings specified in the AFM, and the commuter category discontinued
approach of Sec. 23.67(c)(4). In this NPRM, balked landing refers only
to the all engine balked landing of Sec. 23.77.
The table in paragraph (c) would be changed to show a change in
two-hand roll force from 60 to 50 pounds, which is consistent with JAR
25. The table also would be changed to show a one-hand on the rim roll
force of 25 pounds. This is a JAA/FAA harmonized value.
Section 23.145 Longitudinal Control
Proposed Sec. 23.145 would be revised by changing the speed ranges
applicable to the takeoff, enroute, and landing configurations. In
proposing paragraph (b)(2) the requirement for ``altering and
maintaining, as a minimum, the speed used to show compliance with
Sec. 23.77'' would be changed ``to allow the airspeed to transition
from 1.3 VS0 to 1.3 VS1.'' In proposed paragraph (b)(5) for
landing configuration, the speed reference would be changed from 1.4
VS0 to VREF.
Editorial changes are also proposed for the lead-in to paragraphs
(b) with no substantive change.
Current paragraphs (b)(2)(i) and (ii) would be redesignated as
(b)(2) and (b)(3), respectively.
Proposed paragraph (b)(3) would add more specific requirements if
gated flap positions are used.
Proposed paragraph (b)(4) is the same as current paragraph (b)(4).
Proposed paragraph (b)(5) is the same as current paragraph (b)(5)
except for changes in trim speed to VREF and the allowance of a
two-handed control. Use of two hands is considered appropriate because
the pilot does not need to change power settings.
Proposed paragraph (b)(6) is current paragraph (b)(3).
Proposed paragraph (c) could change the speed range for maneuvering
capability from ``above VMO/MMO and up to VD/MD''
to ``above VMO/MMO and up to the maximum speed shown under
Sec. 23.251.'' This change is considered necessary because a range of
speeds can be chosen as VD/MD. Reference to Sec. 23.251 would
ensure a flight demonstrated speed instead of a design speed.
Proposed paragraph (d) would change the speed that must be
maintained for power-off glide from 1.3 VSO to VREF.
Section 23.147 Directional and Lateral Control
This proposal would make minor revisions to Sec. 23.147(a) and add
two new requirements in proposed paragraphs (b) and (c). The flaps
retracted configuration for Sec. 23.127(a)(4) would be consistent with
the proposed Sec. 23.67.
Proposed Sec. 23.147(b) would add a test for the condition when,
during enroute climb, an engine fails and a time delay of two seconds
occurs before the pilot takes corrective action. The intent of this
proposed change is to test for a likely operational scenario and to
ensure a satisfactory result.
Proposed Sec. 23.147(c) would test for the failure or disconnection
of the primary lateral control. This paragraph requires that the
airplane exhibit adequate dihedral effect throughout the airplane's
operational envelope to ensure continued safe flight and landings if a
lateral control disconnects. In addition, this requirement provides
compatibility with the relaxed requirements of proposed Sec. 23.177(b)
(see proposal for Sec. 23.177).
Section 23.149 Minimum Control Speed
This proposal would clarify Sec. 23.149, add a VMC in the
landing configuration, and provide the procedure for determining a
ground VMC.
Current Sec. 23.149(a) would be revised in the proposal by making
clarifying and editorial changes with no change in requirements.
Section 23.149(b) would be revised by making clarifying changes and
deleting the reference to lesser weights in paragraph (b)(4) because
the range of weights is covered in Sec. 23.21.
Proposed Sec. 23.149(c) specifies the requirement for a VMC in
the landing configuration for WAT and commuter airplanes. This proposed
new requirement is necessary for airplanes in this category to provide
a VREF margin above the VMC determined in the landing
configuration. (See proposal for Sec. 23.73.)
The new Sec. 23.149(f) proposes the requirements for determining a
VMCG for commuter category airplanes, at the option of the
applicant, to comply with Sec. 23.51. (See proposal for Sec. 23.51.)
Section 23.153 Control During Landings
This proposal would revise Sec. 23.153 to reference landing speeds
to VREF and to reorganize the section.
Section 23.155 Elevator Control Forces in Maneuvers
Proposed Sec. 23.155 would make changes to the power and gradient
of the stick force curve.
Proposed Sec. 23.155(b) specifies the maximum continuous power for
the test instead of allowing a power selected by the applicant as an
operating limitation. This revision would eliminate a power
specification that is unnecessary and would simplify normal operations
for the pilot.
Proposed Sec. 23.155(c) addresses stick force gradient to ensure
that stick force lightening is not excessive. The FAA will issue
advisory material on acceptable methods of compliance.
Section 23.157 Rate of Roll
This proposal would revise Sec. 23.157(d) power and trim
requirements and would clarify the flap position. Proposed
Sec. 23.157(d)(1) would clarify that the flaps should be in the landing
position. Proposed Sec. 23.157(d)(3) would make the power consistent
with the approach configuration, which is the configuration being
tested. Proposed Sec. 23.157(d)(4) would relate the trim speed to the
proposed VREF. (See proposal for Sec. 23.73.)
Section 23.161 Trim
This proposal would revise Sec. 23.161 power, configurations, and
speeds.
Proposed Sec. 23.161(a) would state the safety principles
underlying the trim requirements and would provide a regulatory
requirement for considering conditions that might be encountered
outside the requirements addressed in paragraphs (b) through (d).
Proposed Sec. 23.161(b)(1) would add a requirement to trim at
MMO in addition to VMO. This proposed change only clarifies
that the airplane must trim in the Mach limited speed range.
Proposed Sec. 23.161(b)(2) would require lateral and directional
trim over a range of 1.4 VS1 to VH or VMO/MMO for
commuter category airplanes instead of only the high speed requirement
in the present rules. It is appropriate for commuter category airplanes
to trim in the proposed range. It would not be burdensome because all
present commuter category airplanes were designed to the proposed
standard.
The proposed introductory paragraph of Sec. 23.161(c) would delete
the reference to VMO/MMO, since it is addressed in other
appropriate places. Proposed Sec. 23.161(c)(1) would require trim at
takeoff power, as this is a likely operational scenario for most
airplanes and the condition should be tested. In addition, the proposed
change would relate the maximum continuous power climb speeds and
configuration to Sec. 23.69, the enroute climb requirement. Current
Sec. 23.161(c)(2) moves to Sec. 23.161(c)(4), changes the reference
VREF for a landing speed, and adds a requirement for the airplane
to trim at the steepest landing approach gradient the applicant chooses
under Sec. 23.75. It is appropriate for the airplane to trim at all
landing conditions. Current Sec. 23.161(c)(3) moves to
Sec. 23.161(c)(2) with editorial changes. Current Sec. 23.161(c)(4)
moves to Sec. 23.161(c)(3) with an increase in the trim speed from 0.9
VNO or VMO to VNO or VMO/MMO. The increase in
trim speed is appropriate because descent is permitted and is common at
VMO.
Proposed Sec. 23.161(d) would make editorial changes in the
introductory paragraph. It would reference the appropriate Sec. 23.67
requirements and delete commuter category speed ranges, which are moved
to the new Sec. 23.161(e). Section Sec. 23.161(d)(4) is revised to
specify flaps retracted instead of referencing the Sec. 23.67
configurations. Flaps retracted is the likely sustained configuration
where a pilot would need to trim. Also, the flaps retracted
configuration for Sec. 23.161(d)(4) would be consistent with the
proposed Sec. 23.67.
Proposed new Sec. 23.161(e) would ensure that excessive forces are
not encountered in commuter category airplanes during extended climbs
at V2 in the takeoff configuration, when climb above 400 feet is
required.
Section 23.175 Demonstration of Static Longitudinal Stability
This proposal would make changes to Sec. 23.175 power,
configurations, and speeds.
Proposed Sec. 23.175(a)(1) would change the flap position from the
climb position to the flaps retracted position. This is a clarifying
change since virtually all part 23 airplanes use flaps retracted for
climb. Also, this proposed change would align the part 23 and part 25
climb static longitudinal stability requirements.
Proposed Sec. 23.175(a)(3) would delete the option for the
applicant to select some power other than maximum continuous power as
an operating limitation. As noted in the proposed change to
Sec. 23.155, this would eliminate a power specification that is
unnecessary and simplify normal operations for the pilot. Proposed
Sec. 23.175(a)(4) would make the trim speed consistent with the enroute
all-engine climb speed.
The proposed change to Sec. 23.175(b) would rearrange the section
with no change in requirements. The definition of VFC/MMC
contained in Sec. 23.175(b)(2) is proposed to be moved to part 1, to
harmonize with JAR 1. (See the proposed change to Sec. 1.1.)
Current Sec. 23.175(c), which requires the test for gear down
cruise static longitudinal stability, would be deleted. This test is
considered superfluous to the land configuration static longitudinal
stability test and does not represent a likely operating scenario.
Proposed Sec. 23.175(c) would be current Sec. 23.175(d) with only a
change to use VREF as the trim speed.
Section 23.177 Static Directional and Lateral Stability
Proposed revisions to Sec. 23.177 would delete the requirements for
two-control airplanes, make minor clarifying changes, and specify an
exclusion for acrobatic category airplanes.
Proposed Sec. 23.177 would delete the introductory phrase
concerning three-control airplanes, which is consistent with the
deletion of the requirements for two-control airplanes in current
paragraph (b). The two-control airplane regulations were introduced in
1945 but no two-control airplanes have been certificated for several
decades and no need is foreseen for these regulations. If an applicant
proposes a two-control airplane, the FAA would issue special
conditions. After deleting the introductory portion of Sec. 23.177(a),
paragraph (a)(1) would be redesignated as (a). In the first sentence,
the proposed change replaces ``skid'' with ``wings level sideslip'' to
clarify the intended maneuver. Also, the proposed change increases the
power requirement for demonstration of directional stability in the
landing configuration. The current requirement specifies power
necessary to maintain a three degree angle of decent. Maximum
continuous power is considered appropriate since directional stability
should be maintained during a balked landing, particularly since
directional instability is an undesirable characteristic at any point
in the flight envelope. Also, VA is replaced by VO to be
consistent with Sec. 23.1507.
Proposed Sec. 23.177(b), currently (a)(2), replaces ``any'' with
``all'' in the first sentence to clarify that all landing gear and flap
positions must be addressed. Also, the proposed paragraph would specify
a minimum speed at which static lateral stability may not be negative,
as 1.3 VS, for all configurations except takeoff. This is
consistent with the other speeds specified in Sec. 23.177(b) and
relieves the requirement for other than takeoff speeds.
Proposed new Sec. 23.177(c) would provide an exclusion for the
dihedral effect for acrobatic category airplanes approved for inverted
flight. The proposed change recognizes that, in fully acrobatic
airplanes, the dihedral effect is not a desired characteristic.
The addition of proposed Sec. 23.147(c), which ensures lateral
control capability without the use of the primary lateral control
system, compensates for the relieving nature of proposed Sec. 23.177(b)
and the exception from the requirements of Sec. 23.177(b) for acrobatic
category airplanes.
Present Sec. 23.177(a)(3) is redesignated as Sec. 23.177(d). The
proposed Sec. 23.177(d) deletes the next to the last sentence,
concerning bank angle and heading, because the current requirement is
not a necessary test condition and a constant heading during the
sideslip may be impossible in some airplanes.
Present Sec. 23.177(b) is deleted, as previously discussed, because
it applies to two-control airplanes.
Section 23.201 Wings Level Stall
This proposal would delete both two-control airplanes and altitude
loss requirements and would make clarifying changes in Sec. 23.201.
The proposed change to Sec. 23.201(a) deletes the applicability
reference for an airplane with independently controlled roll and
directional controls. The last word, ``pitches'' is replaced by
``stalls'' since stalls may be defined by other than nose-down
pitching.
Present Sec. 23.201(b) is deleted since it applies to two-control
airplanes. (See proposed change for Sec. 23.177 for discussion of two-
control airplane requirements.)
Current Sec. 23.201(c) is divided into proposed Sec. 23.201 (b) and
(c). Proposed Sec. 23.201(b) covers stall recognition and proposed
Sec. 23.201(c) addresses stall recovery. Proposed Sec. 23.201(b)
clarifies that the test should start from a speed at least 10 knots
above the stall speed. Proposed Sec. 23.201(b) has no change in
requirements. Section 23.201(c) is changed to specify how long the
control must be held against the stop. This change would ensure that
the procedure for determining stall speed is the same procedure used to
test stall characteristics. The last sentence of current paragraph (c)
on the increase of power is deleted because it would only apply to
altitude loss.
Present Sec. 23.201(d) would be deleted, as suggested by the JAA,
since the determination of altitude loss, and its subsequent furnishing
in the AFM, is not considered information useful to the pilot for safe
operation of the airplane.
Proposed Sec. 23.201(d) would be based on present Sec. 23.210(e)
and would be revised to clarify that the roll and yaw limits apply
during both entry and recovery.
Proposed Sec. 23.201(e) is present paragraph (f) with some
revisions. During FAR/JAR harmonization meetings, the JAA pointed out
to the FAA that in high power-to-weight ratio airplanes, extreme nose-
up attitudes were the principal criteria for use of reduced power, not
the presence of undesirable stall characteristics. The FAA concurs and
proposes to delete the phrase concerning stall characteristics.
Section 23.203 Turning Flight and Accelerated Turning Stalls
Proposed Sec. 23.203 would be revised by adding the word
``turning'' before ``stalls'' and after ``accelerated'' in the heading,
the introductory text, and in proposed paragraphs (a)(2) and (b)(5).
This proposed change clarifies that accelerated stalls are performed in
turning flight. Also, it clarifies the definition to show that
accelerated stalls are not intended to be performed in straight flight.
This clarification reflects current practice.
Proposed Sec. 23.203 (a) and (b) would reference the stall
definition in Sec. 23.201(b), which is more specific than the present
general words ``when the stall has fully developed or the elevator has
reached its stop.''
For clarification, current paragraph (b)(4) would be separated into
proposed paragraphs (b)(4) and (b)(5) without substantive change, and
current paragraph (b)(5) would be redesignated as paragraph (b)(6).
Proposed Sec. 23.203(c)(1) would clarify the wing flap positions by
changing ``each intermediate position'' to ``each intermediate normal
operating position.''
The proposed change to Sec. 23.203(c)(4) would clarify the use of
reduced power. (See the proposed change to Sec. 23.201(f).)
Proposed new paragraph (c)(6) has been added to be consistent with
new Sec. 23.207(c)(6) configurations (Amendment No. 23-45).
Section 23.205 Critical Engine-Inoperative Stalls
This proposal would delete Sec. 23.205. The present requirement to
demonstrate stalls with the critical engine inoperative is restricted
to the enroute configuration and to a level of power asymmetry with
which the airplane is controllable with wings level at the stalling
speed. As a result, the power on the operating engines at the stall is
normally fairly low, and neither the configuration nor the power
setting represent the conditions most likely to accompany an
inadvertent stall in service. Reduction of power of the operating
engine(s) during the recovery is permitted, and it is questionable
whether such action would be taken promptly in an inadvertent stall in
service. Experience shows that stalls with significant power asymmetry
can result in a spin, even on airplanes that are certificated to the
present requirement. Apparently the requirement for demonstrating one-
engine-inoperative stalls is not effective in ensuring that inadvertent
stalls in service with one engine inoperative will have satisfactory
characteristics and be recoverable. Sufficient protection against the
hazard of stalling with one engine inoperative is provided by the one-
engine-inoperative performance requirements and operating speed
margins, coupled with the requirements for determination of VMC,
the addition of a directional and lateral control test under
Sec. 23.147(b), and demonstration of stalling characteristics with
symmetric power.
Section 23.207 Stall Warning
This proposal would delete the upper limit on stall speed margin
and provide for mutable stall warning on acrobatic category airplanes
in Sec. 23.207.
Proposed Sec. 23.207(c) would reference the stall tests required by
Sec. 23.201(b) and Sec. 23.203(a)(1) and specify that during such tests
for one knot per second deceleration stalls, both wings level and
turning, the stall must begin at a speed exceeding the stalling speed
by a margin of not less than 5 knots. The quantified upper limit in the
current rule of 10 knots or 15 percent of the stalling speed would be
deleted. The upper limit has created problems for manufacturers because
of the complex design features required to show compliance. The upper
limit requirement was in effect replaced by the nuisance stall warning
requirement in Sec. 23.207.(d).
Present Sec. 23.207(d) would be divided and moved to proposed
Sec. 23.207 (d) and (e). Proposed Sec. 23.207(d) on nuisance stall
warnings would have no change in requirements. Proposed Sec. 23.207(e)
would delete the bottom limit of five knots for decelerations greater
than one knot per second. Also, it would specify that the stall warning
must begin sufficiently before the stall so that the pilot can take
corrective action. This is considered appropriate because, at the
higher deceleration rates of three to five knots per second, a
specified five knots may not be enough stall warning.
Proposed new Sec. 23.207(f) allows for a mutable stall warning
system for acrobatic category airplanes, with automatic arming for
takeoff and rearming for landing. This feature is useful for acrobatic
pilots and provides safeguards for takeoff and landing.
Secion 23.221 Spinning
This proposal would revise the point to start the one-turn-spin
recovery count, delete the ``characteristically incapable of spinning''
option, and make minor changes in acrobatic category spins in
Sec. 23.221.
Proposed Sec. 23.221(a) would replace the exception for airplanes
characteristically incapable of spinning with an exception for
airplanes that demonstrate compliance with the optional spin resistant
requirements of paragraph (a)(2) of this section. Criteria for an
airplane incapable of spinning are unnecessary since criteria for spin
resistant airplanes are provided. Proposed Sec. 23.221(a) would change
the point at which the count for the one-turn-spin recovery begins. The
change would specify a more specific point to begin the count by
replacing the current phrase ``after the controls have been applied''
with ``after initiation of the first control action for recovery.''
Under the present rules, if an applicant proposes a multiple step
recovery procedure that starts with the rudder, then the airplane may
be effectively recovered before the start of the recovery count.
Proposed Sec. 23.221(a)(1)(ii) would specify that no control force
or characteristic can adversely affect prompt recovery. This would be
an improvement over the present prohibition of excessive back pressure
in current Sec. 23.221(a)(1)(ii).
Present Sec. 23.221(a)(1) is proposed to be recodified into
Sec. 23.221(a)(1)(i) through (a)(1)(iv) with no changes in the
requirements. Present Sec. 23.221(a)(2) on spin resistant airplanes
would be restated with minor editorial changes but with no change in
requirements.
Proposed Sec. 23.221(b) would specify the emergency egress
requirements of Sec. 23.807(b)(5) for those utility category airplanes
approved for spinning. This is considered an appropriate way to cross-
reference the requirements of Sec. 23.807 to the flight requirements.
The proposed Sec. 23.221(c) introductory paragraph would require
acrobatic category airplanes to meet the one-turn-spin requirements of
Sec. 23.221(a). This change is proposed because acrobatic category
airplanes should have sufficient controllability to recover from the
developing one-turn-spin under the same conditions as normal category
airplanes. The proposed introductory paragraph would also cross-
reference Sec. 23.807 for emergency egress requirements.
Proposed Sec. 23.221(c) pertaining to acrobatic category airplanes
would add a requirement in proposed paragraph (c)(1) for spin recovery
after six turns or any greater number of turns for which certification
is requested. The proposed rule would require recovery within 1.5 turns
after initiation of the first control action for recovery. This
proposed requirement would ensure recovery within 1.5 turns if the spin
mode changes beyond six turns. As an alternative, the applicant may
stop at six turns and provide a limitation of six turns.
Proposed Sec. 23.221(c)(2) would delete the option to retract flaps
during recovery and would provide the applicant with a choice of flaps
up or flaps deployed for spin approval. The paragraph would continue to
prohibit exceeding applicable airspeed limits and limit maneuvering
load factors.
A new Sec. 23.221(c)(4) is proposed to ensure that the acrobatic
spins do not cause pilot incapacitation.
The present Sec. 23.221(d) is proposed to be deleted. The
recognition of airplanes that are ``characteristically incapable of
spinning'' has been in the regulation since at least 1937. In 1942, the
present weight, center of gravity, and control mis-rig criteria were
introduced into Civil Air Regulation (CAR) 03. Since then, the National
Aeronautics and Space Administration (NASA) spin resistant
requirements, which are based on research, have been developed and
incorporated in the regulations by Amendment No. 23-42 (56 FR 344,
January 3, 1991). If an applicant proposes a non-spinable airplane, it
would be appropriate to apply the more technologically advanced
requirements of proposed Sec. 23.221(a)(2); therefore, Sec. 23.221(d)
would be deleted.
Section 23.233 Directional Stability and Control
This proposal would make minor word changes to Sec. 23.233(a) to
harmonize this section with the corresponding JAR section.
Section 23.235 Operation on Unpaved Surfaces
This proposal would revise the heading of Sec. 23.235 and delete
water operating requirements, which are moved to proposed new
Sec. 23.237.
Section 23.237 Operation on Water
Proposed new Sec. 23.237, for operation on water, is essentially
the same as the current Sec. 23.235(b).
Section 23.253 High Speed Characteristics
This proposal would delete the current paragraph (b)(1), since the
requirement for piloting strength and skill is covered in Sec. 23.141.
Section 23.562 Emergency Landing Dynamic Conditions
This proposal would change the one engine inoperative climb
reference in Sec. 23.562(d) to Sec. 23.67(a)(1).
Section 23.1325 Static Pressure System
This proposal would revise Sec. 23.1325(e) to clarify that the
calibration must be conducted in flight, which is standard practice.
The text of Sec. 23.1325(f) would be removed and the paragraph would be
reserved. The text of paragraph (g) would be moved to paragraph (f) in
a future rulemaking action. The results of the calibration would be
required in the proposed Sec. 23.1587.
Section 23.1511 Flap Extended Speed
This proposal would delete from Sec. 23.1511(a) references to
Sec. 23.457 because Sec. 23.457 is proposed to be deleted from the FAR
in a related NPRM on airframes, Notice No. 94-20 (59 FR 35196, July 8,
1994).
Section 23.1521 Powerplant Limitations
This proposal would require, under Sec. 23.1521, maximum
temperature to be established for takeoff operation and would require
an ambient temperature limit for reciprocating engines in airplanes of
more than 6,000 pounds.
Proposed Sec. 23.1521(b)(5) would require the establishment of
maximum cylinder head, liquid coolant, and oil temperature limits for
takeoff operation without regard to the allowable time. Presently,
temperature limits are required only if the takeoff power operation is
permitted for more than two minutes. It is appropriate to require
operating temperature limitations because most takeoff operations will
exceed two minutes.
Proposed Sec. 23.1521(e) would require an ambient temperature limit
for turbine engine-powered airplanes and reciprocating engine-powered
airplanes over 6,000 pounds. This change is proposed because these
airplanes are subject to WAT limits and it will ensure that airplane
engines will cool at the ambient temperature limit.
Section 23.1543 Instrument Markings: General
Proposed new Sec. 23.1543(c) would require that all related
instruments be calibrated in compatible units. This is considered
essential for safe operation.
Section 23.1545 Airspeed Indicator
Proposed revisions to Sec. 23.1545 would differentiate between WAT
limited and non-WAT limited airplanes in Sec. 23.1545.
Proposed Sec. 23.1545(b)(5) would delete any one-engine-inoperative
best rate of climb speed marking requirements for WAT limited
airplanes. These airplanes would already have scheduled speeds in case
of an engine failure. Proposed paragraph (b)(5) would apply only to
non-WAT airplanes for which the one-engine-inoperative best rate of
climb speed marking has been simplified to sea level at maximum weight.
Since the blue arc rule was promulgated in Amendment No. 23-23 (43 FR
50593, October 30, 1978), certification experience has shown that the
marking of an arc is unnecessarily complicated. For many airplanes, the
arc was so narrow that the arc was a line. Therefore, proposed
paragraph (b)(5) would require a blue radial line instead of an arc.
Proposed Sec. 23.1545(b)(6) would retain the same VMC
requirement for non-WAT airplanes and delete any VMC markings for
WAT airplanes since WAT airplanes already have scheduled speeds in case
of engine failure.
Section 23.1553 Fuel Quantity Indicator
This proposal would delete, from Sec. 23.1553, the use of an arc to
show a quantity of unusable fuel. The proposed rule references the
unusable fuel determination and requires only a red radial line, which
would provide a clearer indication of fuel quantity for pilots.
Section 23.1555 Control Markings
This proposal would add to Sec. 23.1555(e)(2) the requirement that
no other control be red. This would help prevent use of a wrong control
in an emergency.
Section 23.1559 Operating Limitations Placard
This proposal would simplify the present Sec. 23.1559 and delete
duplicate material.
Proposed Sec. 23.1559(a), (b), and a new paragraph (c), would
provide essentially the same information as the current rule. All
airplanes currently operate with an AFM and the new rule places
emphasis on using the AFM to define required operating limitations.
Section 23.1563 Airspeed Placards
This proposal would add a new paragraph (c) to Sec. 23.1563. The
new paragraph would be applicable to WAT limited airplanes and would
require providing the maximum VMC in the takeoff configuration
determined under Sec. 23.149(b). This is desirable since the VMC
is not marked on the airspeed indicator for these airplanes.
Section 23.1567 Flight Maneuver Placard
Proposed new Sec. 23.1567(d), which would be applicable to
acrobatic and utility airplanes approved for intentional spinning,
would require a placard listing control actions for recovery. Also, it
would require a statement on the placard that the airplane be recovered
when spiral characteristics occur, or after six turns, or at any
greater number of turns for which certification tests have been
conducted. This paragraph would replace the similar placard requirement
in current Sec. 23.1583(e)(3) for acrobatic category airplanes, and the
placard requirement would be deleted from Sec. 23.1583(e).
Section 23.1581 General
This proposal would make editorial changes in Sec. 23.1581 and
would recognize WAT limited and non-WAT limited airplanes.
Proposed new Sec. 23.1581(a)(3) would require information necessary
to comply with relevant operating rules. This is a FAR/JAR
harmonization item and is considered necessary because some operational
rules, such as Sec. 135.391, require flight planning with one-engine-
inoperative cruise speed and/or driftdown data. For airplanes operated
under part 135 in the United States, it represents no change in
requirements.
Proposed Sec. 23.1581(b)(2) would require that only WAT limited
airplane AFM's provide data necessary for determining WAT limits.
Proposed new Sec. 23.1581(c) would require the AFM units to be the
same as on the instruments. This requirement would enhance operational
safety.
Proposed Sec. 23.1581(d) would delete the current requirement for a
table of contents. This is considered to be a format requirement and
not appropriate for this section, which specifies AFM content. Current
Sec. 23.1581(d) is being replaced by a requirement to present all
operational airspeeds as indicated airspeeds. Although not currently
required, this is current practice.
Section 23.1583 Operating Limitations
Proposed revisions to Sec. 23.1583 would make minor changes in the
operating limitations information furnished in the AFM. These proposed
changes include revising airspeed limitations for commuter category
airplanes, requiring AFM limitations for WAT limited airplanes,
furnishing ambient temperature limitations, furnishing smoking
restriction information, and furnishing information specifying types of
runway surfaces.
Proposed Sec. 23.1583(a)(3) would make the VMO/VMO
airspeed operating limitations applicable only to turbine powered
commuter category airplanes. This is consistent with current practice
since no reciprocating engine-powered commuter category airplanes have
been proposed.
Proposed Sec. 23.1583(c)(3) would add takeoff and landing weight
limitations for WAT limited airplanes. (See the Sec. 23.45 proposal for
discussion of WAT limited airplanes.)
Proposed Sec. 23.1583(c)(4) and (5) renumber the present
Sec. 23.1583(c)(3) and (4). These proposed paragraphs are revised
editorially and cross-references are updated. Proposed paragraph
(c)(4)(ii) would impose a new requirement that the AFM include the
maximum takeoff weight for each airport altitude and ambient
temperature within the range selected by the applicant at which the
accelerate-stop distance determined under Sec. 23.55 is equal to the
available runway length plus the length of any stopway, if available.
This is currently required for transport category airplanes and is
necessary for harmonization with the JAR.
Proposed new Sec. 23.1583(c)(6) would establish the zero wing fuel
weight of Sec. 23.343 as a limitation. This would provide the pilot
with information necessary to prevent exceeding airplane structural
limits.
Proposed new Sec. 23.1583(d) has editorial changes only.
Proposed new Sec. 23.1583(e)(1) and (2) would delete references to
``characteristically incapable of spinning.'' As discussed under
Sec. 23.221, requirements for ``characteristically incapable of
spinning'' would be deleted.
Proposed new Sec. 23.1583(e)(3) and (4) would replace present
paragraph (e)(3). Proposed Sec. 23.1583(e)(4) would add the requirement
for specifying limitations associated with spirals, six turn spins, or
more than six turn spins. The requirement for a placard has been
deleted since the requirement would be covered in Sec. 23.1567.
Proposed new Sec. 23.1583(e)(5) would be based on current paragraph
(e)(4) for commuter category airplanes. It would be revised to define
the maneuvers as those proposed for commuter category airplanes in
Sec. 23.3.
Proposed new Sec. 23.1583(f) would revise the heading of the
paragraph and add the limit negative load factor for acrobatic category
airplanes. The limit negative load factor is essential for safe
operational use.
Proposed new Sec. 23.1583(g) would make editorial changes with no
change in requirements. The paragraph would reference the requirements
of flight crews in Sec. 23.1523.
Proposed Sec. 23.1583 (i), (j) and (k) are the current
Sec. 23.1583(k), (l) and (m), as redesignated.
Proposed new Sec. 23.1583(l) would require furnishing baggage and
cargo loading limits.
Proposed new Sec. 23.1583(m) would require furnishing any special
limitations on systems and equipment. This would provide the pilot with
information necessary for safe operation of the airplane systems and
equipment.
Proposed new Sec. 23.1583(n) would require a statement on ambient
temperature limitations. Maximum cooling temperature limits have been
required for turbine powered airplanes by Sec. 23.1521(e); however, the
requirement for the limitation has never been specified in
Sec. 23.1583. Proposed Sec. 23.1583(n) would require furnishing both
maximum and minimum temperature limits if appropriate. A minimum
temperature limit would provide the pilot with information necessary to
avoid airplane damage during low temperature operations.
Proposed new Sec. 23.1583(o) would require furnishing any occupant
smoking limitations on the airplane. This would enhance safe operation
of the airplane.
Proposed new Sec. 23.1583(p) would require the applicant to state
what runway surfaces have been approved. This provides the pilot with a
positive indication of which runway types may be used.
Section 23.1585 Operating Procedures
This proposal would rearrange the current material in Sec. 23.1585
and add additional requirements as discussed below.
Proposed Sec. 23.1585(a) would contain the requirements applicable
to all airplanes. The requirements would be arranged in a different
order from the current requirements in paragraph (a). The requirements
for information that must be included cover--unusual flight or ground
handling characteristics; maximum demonstrated values of crosswinds;
recommended speed for flight in rough air; restarting an engine in
flight; and making a normal approach and landing in accordance with
Sec. 23.73 and Sec. 23.75. All of these requirements are in current
Sec. 23.1585(a) except for restarting a turbine engine in flight, which
is in current paragraph (c)(5) pertaining only to multiengine
airplanes. The FAA decided that a restart capability is not required
for single reciprocating engine airplanes for the reasons given in the
preamble discussion of proposal 3 in Amendment No. 23-43 (58 FR 18958,
April 9, 1993). The requirement for providing restart information
should apply to single turbine engines, since turbine engine designs
incorporate a restart capability and inadvertent shutdowns may occur.
Normal approach and landing information in accordance with the landing
requirement in proposed Sec. 23.73 and Sec. 23.75 is new. This is
necessary to enable pilots to achieve the published landing distances
and, if necessary, to safely transition to a balked landing.
Proposed Sec. 23.1585(b) would be a revision of Sec. 23.1585(b) on
gliding after an engine failure for single-engine airplanes. The
proposed version would reference requirements in proposed Sec. 23.71.
Proposed Sec. 23.1585(c) for multiengine airplanes would require
compliance with (a) plus the following information requirements from
current paragraph (c): approach and landing with an engine inoperative;
balked landing with an engine inoperative; and VSSE as determined
in Sec. 23.149. Current paragraph (c) requirements for information on
procedures for continuing a takeoff following an engine failure and
continuing a climb following an engine failure would be moved to
proposed (e) for normal, utility, and acrobatic multiengines.
Proposed Sec. 23.1585(d) would apply to normal, utility and
acrobatic airplanes. These airplanes would have to comply with
paragraph (a) and either (b) or (c). These airplanes would also have to
comply with the normal takeoff, climb, and the abandoning a takeoff
procedures, which are currently contained in paragraph (a).
As discussed above, Sec. 23.1585(c), for normal, utility and
acrobatic multiengine airplanes, would require compliance with proposed
(a), (c), and (d) plus requirements for continuing a takeoff or climb
with one engine inoperative, which are now in current paragraph (c) (1)
and (2).
Proposed Sec. 23.1585(f) would require commuter category airplanes
to comply with paragraphs (a) and (c) plus the normal takeoff
requirements from current paragraph (a)(2) revised; accelerate-stop
requirements, which are new, and continuing takeoff after engine
failure, which are in current paragraph (c)(1).
Proposed Sec. 23.1585(g) would be the same as current paragraph (d)
on identifying operating conditions, which necessitate fuel system
independence.
Proposed Sec. 23.1585(h) would be the same as current paragraph (e)
for disconnecting the battery from its charging source.
Proposed Sec. 23.1585(i) is based on current paragraph (g) on the
total quantity of usable fuel and adds information on the effect of
pump failure on unusable fuel.
Proposed new Sec. 23.1585(j) would require procedures for safe
operation of the airplanes' systems and equipment. Although not
currently required, this is current industry practice.
Present Sec. 23.1585(h), commuter category airplane procedures for
restarting turbine engines in flight, would no longer be necessary
because the requirement would be covered under paragraph (a)(4).
Section 23.1587 Performance Information
Proposed Sec. 23.1587 would rearrange existing material, delete ski
plane performance exceptions, delete the option of calculating
approximate performance, delete stall altitude loss data, and require
overweight landing performance in Sec. 23.1587. Stalling speed
requirements of current paragraph (c) (2) and (3) would be combined and
moved to paragraph (a)(1) and would reference the stalling speed
requirement of Sec. 23.49. Information on the steady rate and gradient
of climb with all engines operating would be required by proposed
paragraph (a)(2). This is revised from current paragraph (a)(2). The
reference would be changed to proposed Sec. 23.69(a).
Proposed (a)(3) would require, as is now required, that landing
distance be determined under Sec. 23.75, and would add that this must
be provided for each airport altitude, standard temperature, and type
of surface for which it is valid. Proposed paragraph (a)(4) would
require information on the effect on landing distance when landing on
other than hard surface, as determined under Sec. 23.45(g). Proposed
paragraph (a)(5) would cover information on the effects on landing
distance of runway slope and wind. This would provide the pilot with
data with which to account for these factors in his or her takeoff
calculations.
Current requirements in Sec. 23.1587(b) on ski planes would be
deleted. Proposed paragraph (b) would add a steady angle of climb/
descent requirement as determined under Sec. 23.77(a). This requirement
would apply to all non-WAT airplanes.
Proposed paragraph (c) would apply to normal, utility, and
acrobatic category airplanes, rather than all airplanes as in current
paragraph (c). The proposed (c) would delete stall altitude loss
requirements that are in current paragraph (c)(1). As mentioned,
current stalling speed requirements would be moved to proposed
paragraph (a)(1). Current paragraph (c)(4) on cooling climb speed data
would also be deleted since all airplanes would cool at scheduled
speeds.
Proposed paragraph (c)(1) would pertain to the takeoff distance
determined under Sec. 23.53 and the type of surface. Proposed paragraph
(c)(2) and (c)(3) pertain to the effect on takeoff distance of the
runway surface, slope, and headwind and tailwind component.
Proposed paragraph (c)(4) would impose a new requirement pertaining
to the one-engine inoperative takeoff climb/descent performance for
WAT-limited airplanes. This pertains only to reciprocating engine-
powered airplanes. It would provide the pilot with the information
determined under proposed Sec. 23.66.
Proposed paragraph (c)(5) pertains to enroute rate and gradient of
climb/descent determined under Sec. 23.69(b), for multiengine
airplanes.
Proposed Sec. 23.1587(d) for commuter category airplanes would
incorporate the present data plus the addition of accelerate-stop data,
overweight landing performance, and the effect of operation on other
than smooth hard surfaces. In addition, in order to consolidate all of
the requirements for what must appear in the AFM in subpart G, proposed
Sec. 23.1587(d)(10) would contain the requirement, found in existing
Sec. 23.1323(d), to show the relationship between IAS and CAS in the
AFM.
Section 23.1589 Loading Information
Proposed Sec. 23.1589(b) would make editorial changes to simplify
the text, with no change in requirements.
Appendix E
Appendix E would be deleted for the reasons given in the proposed
change to Sec. 23.25.
Preliminary Regulatory Evaluation, Initial 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 impact 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 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
Of the 57 sections that would be amended or added in this proposed
rule, the FAA has identified 15 that could result in additional
compliance costs in one or more airplane categories. Amendments to five
sections could result in cost savings. The greatest costs would be
incurred by manufacturers of WAT limited airplanes (e.g., multiengine
airplanes with maximum weights of more than 6,000 pounds). When
amortized over a production run, the quantified incremental costs would
be relatively modest--less than $100 per airplane. The FAA solicits
comments concerning the incremental certification/development costs
attributable to the proposed rule.
The primary benefit of the proposed rule would be the cost
efficiencies of harmonization with the JAR for those manufacturers that
choose to market airplanes in JAA countries as well as to manufacturers
in JAA countries that choose to market airplanes in the U.S. Other
benefits of the proposed rule would be decreased reliance on special
conditions, simplification of the certification process through
clarification of existing requirements, and increased flexibility
through optional designs.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily and
disproportionately burdened by Federal 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. Based on FAA Order 2100.14A,
Regulatory Flexibility Criteria and Guidance, the FAA has determined
that the proposed amendments would not have a significant economic
impact on a substantial number of small entities.
International Trade Impact Assessment
The proposed rule would not constitute a barrier to international
trade, including the export of American airplanes to foreign countries
and the import of foreign airplanes into the United States. Instead,
the proposed flight certification procedures would be harmonized with
those of the JAA and would lessen restraints on trade.
Federalism Implications
The regulation 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 flight airworthiness standards for
normal, utility, acrobatic, and commuter category airplanes to be
compatible with the same standards that will be proposed for the same
category airplanes by the Joint Airworthiness Authority in Europe. If
adopted, the proposed revision would reduce the regulatory burden on
the United States and European airplane manufacturers by relieving them
of 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 a significant regulatory action. In
addition, the FAA certifies that this proposal, if adopted, will not
have a significant economic impact 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 1
Air transportation.
14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
The Proposed Amendment
In consideration of the foregoing, the Federal Aviation
Administration proposes to amend parts 1 and 23 of the Federal Aviation
Regulations (14 CFR parts 1 and 23) as follows:
PART 1--DEFINITIONS AND ABBREVIATIONS
1. The authority citation for part 1 continues to read as follows:
Authority: 49 U.S.C. app. 1347, 1348, 1354(a), 1357(d)(2), 1372,
1421 through 1430, 1432, 1442, 1443, 1472, 1510, 1522, 1652(e),
1655(c), 1657(f); 49 U.S.C. 106(g).
2. A new definition is added in alphabetical order to Sec. 1.1 to
read as follows:
Sec. 1.1 General definitions.
* * * * *
Maximum speed for stability characteristics, VFC/MFC
means a speed that may not be less than a speed midway between maximum
operating limit speed (VMO/MMO) and demonstrated flight
diving speed (VDF/MDF), except that, for altitudes where the
Mach number is the limiting factor, MFC need not exceed the Mach
number at which effective speed warning occurs.
* * * * *
PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND
COMMUTER CATEGORY AIRPLANES
3. The authority citation for part 23 is revised 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).
4. Section 23.3 is amended by revising paragraphs (b)(2), (d), and
(e) to read as follows:
Sec. 23.3 Airplane categories.
* * * * *
(b) * * *
(2) Lazy eights, chandelles, and steep turns, or similar maneuvers,
in which the angle of bank is more than 60 degrees but not more than 90
degrees.
* * * * *
(d) The commuter category is limited to propeller-driven,
multiengine airplanes that have a seating configuration, excluding
pilot seats, of 19 or less, and a maximum certificated takeoff weight
of 19,000 pounds or less. The commuter category operation is limited to
any maneuver incident to normal flying, stalls (except whip stalls),
and steep turns, in which the angle of bank is not more than 60
degrees.
(e) Except for commuter category, airplanes may be type certified
in more than one category if the requirements of each requested
category are met.
5. Section 23.25 is amended by revising paragraphs (a) introductory
text and (a)(1) introductory text, and paragraphs (a)(1)(i) and
(a)(1)(iii) to read as follows:
Sec. 23.25 Weight limits.
(a) Maximum weight. The maximum weight is the highest weight at
which compliance with each applicable requirement of this part (other
than those complied with at the design landing weight) is shown. The
maximum weight must be established so that it is--
(1) Not more than the least of--
(i) The highest weight selected by the applicant; or
* * * * *
(iii) The highest weight at which compliance with each applicable
flight requirement is shown, and
* * * * *
6. Section 23.33 is amended by revising paragraphs (b) (1) and (2)
to read as follows:
Sec. 23.33 Propeller speed and pitch limits.
(b) * * *
(1) During takeoff and initial climb at the all engine(s) operating
climb speed specified in Sec. 23.65, the propeller must limit the
engine r.p.m., at full throttle or at maximum allowable takeoff
manifold pressure, to a speed not greater than the maximum allowable
takeoff r.p.m.; and
(2) During a closed throttle glide, at VNE, the propeller may
not cause an engine speed above 110 percent of maximum continuous
speed.
* * * * *
7. Section 23.45 is revised to read as follows:
Sec. 23.45 General.
(a) Unless otherwise prescribed, the performance requirements of
this part must be met for--
(1) Still air and standard atmosphere; and
(2) Ambient atmospheric conditions, for commuter category
airplanes, for reciprocating engine-powered airplanes or more than
6,000 pounds maximum weight, and for turbine engine-powered airplanes.
(b) Performance data must be determined over not less than the
following ranges of conditions--
(1) Airport altitudes from sea level to 10,000 feet; and
(2) For reciprocating engine-powered airplanes of 6,000 pounds, or
less, maximum weight, temperature from standard to 30 deg.C above
standard; or
(3) For reciprocating engine-powered airplanes of more than 6,000
pounds maximum weight and turbine engine-powered airplanes, temperature
from standard to 30 deg.C above standard, or the maximum ambient
atmospheric temperature at which compliance with the cooling provisions
of Sec. 23.1041 to Sec. 23.1047 is shown, if lower.
(c) Performance data must be determined with the cowl flaps or
other means for controlling the engine cooling air supply in the
position used in the cooling tests required by Sec. 23.1041 to
Sec. 23.1047.
(d) The available propulsive thrust must correspond to engine
power, not exceeding the approved power, less--
(1) Installation losses; and
(2) The power absorbed by the accessories and services appropriate
to the particular ambient atmospheric conditions and the particular
flight condition.
(e) The performance, as affected by engine power or thrust, must be
based on a relative humidity:
(1) Of 80 percent, at and below standard temperature; and
(2) From 80 percent at the standard temperature, varying linearly
down to 34 percent at the standard temperature plus 50 deg.F.
(f) Unless otherwise prescribed, in determining the takeoff and
landing distances, changes in the airplane's configuration, speed, and
power must be made in accordance with procedures established by the
applicant for operation in service. These procedures must be able to be
executed consistently by pilots of average skill in atmospheric
conditions reasonably expected to be encountered in service.
(g) The following, as applicable, must be determined on a smooth,
dry, hard-surfaced runway--
(1) Takeoff distance of Sec. 23.53(b);
(2) Accelerate-stop distance of Sec. 23.55;
(3) Takeoff distance and takeoff run of Sec. 23.59; and
(4) Landing distance of Sec. 23.75.
The effect on these distances of operation on other types of surfaces
(for example, grass, gravel) when dry, may be determined or derived and
these surfaces listed in the Airplane Flight Manual in accordance with
Sec. 23.1583(p).
(h) For commuter category airplanes, the following also apply:
(1) Unless otherwise prescribed, the applicant must select the
takeoff, enroute, approach, and landing configurations for the
airplane.
(2) The airplane configuration may vary with weight, altitude, and
temperature, to the extent that they are compatible with the operating
procedures required by paragraph (h)(3) of this section.
(3) Unless otherwise prescribed, in determining the critical-
engine-inoperative takeoff performance, takeoff flight path, and
accelerate-stop distance, changes in the airplane's configuration,
speed, and power must be made in accordance with procedures established
by the applicant for operation in service.
(4) Procedures for the execution of discontinued approaches and
balked landings associated with the conditions prescribed in
Sec. 23.67(c)(4) and Sec. 23.77(c) must be established.
(5) The procedures established under paragraphs (h)(3) and (h)(4)
of this section must--
(i) Be able to be consistently executed by a crew of average skill
in atmospheric conditions reasonably expected to be encountered in
service;
(ii) Use methods or devices that are safe and reliable; and
(iii) Include allowances for any reasonably expected time delays in
the execution of the procedures.
8. Section 23.49 is revised to read as follows:
Sec. 23.49 Stalling speed.
(a) VS0 and VS1 are the stalling speeds or the minimum
steady flight speeds, in knots (CAS), at which the airplane is
controllable with--
(1) For reciprocating engine-powered airplanes, the engine(s)
idling, the throttle(s) closed or at not more than the power necessary
for zero thrust at a speed not more than 110 percent of the stalling
speed;
(2) For turbine engine-powered airplanes, the propulsive thrust not
greater than zero at the stalling speed, or, if the resultant thrust
has no appreciable effect on the stalling speed, with engine(s) idling
and throttle(s) closed;
(3) The propeller(s) in the takeoff position;
(4) The airplane in the condition existing in the test, in which
VS0 and VS1 are being used;
(5) The center of gravity in the position that results in the
highest value of VS0 and VS1; and
(6) The weight used when VS0 or VS1 are being used as a
factor to determine compliance with a required performance standard.
(b) VS0 and VS1 must be determined by flight tests, using
the procedure and meeting the flight characteristics specified in
Sec. 23.201.
(c) Except as provided in paragraph (d) of this section, VS0
at maximum weight must not exceed 61 knots for--
(1) Single-engine airplanes; and
(2) Multiengine airplanes of 6,000 pounds or less maximum weight
that cannot meet the minimum rate of climb specified in
Sec. 23.67(a)(1) with the critical engine inoperative.
(d) All single-engine airplanes, and those multiengine airplanes of
6,000 pounds or less maximum weight with a VS0 of more than 61
knots that do not meet the requirements of Sec. 23.67(a)(1), must
comply with Sec. 23.562(d).
9. Section 23.51 is revised to read as follows:
Sec. 23.51 Takeoff speeds.
(a) For normal, utility, and acrobatic category airplanes, rotation
speed, VR, is the speed at which the pilot makes a control input,
with the intention of lifting the airplane out of contact with the
runway or water surface.
(1) For multiengine landplanes, VR must not be less than the
greater of 1.05 VMC or 1.10 VS1;
(2) For single-engine landplanes, VR, must not be less than
VS1; and
(3) For seaplanes and amphibians taking off from water, VR,
may be any speed that is shown to be safe under all reasonably expected
conditions, including turbulence and complete failure of the critical
engine.
(b) For normal, utility, and acrobatic category airplanes, the
speed at 50 feet above the takeoff surface level must not be less than:
(1) For multiengine airplanes, the highest of--
(i) A speed that is shown to be safe for continued flight (or
emergency landing, if applicable) under all reasonably expected
conditions, including turbulence and complete failure of the critical
engine;
(ii) 1.10 VMC; or
(iii) 1.20 VS1.
(2) For single-engine airplanes, the higher of--
(i) A speed that is shown to be safe under all reasonably expected
conditions, including turbulence and complete engine failure; or
(ii) 1.20 VS1.
(c) For commuter category airplanes, the following apply:
(1) V1 must be established in relation to VEF as follows:
(i) VEF is the calibrated airspeed at which the critical
engine is assumed to fail. VEF must be selected by the applicant
but must not be less than 1.05 VMC determined under Sec. 23.149(b)
or, at the option of the applicant, not less than VMCG determined
under Sec. 23.149(f).
(ii) The takeoff decision speed, V1, is the calibrated
airspeed on the ground at which, as a result of engine failure or other
reasons, the pilot is assumed to have made a decision to continue or
discontinue the takeoff. The takeoff decision speed, V1, must be
selected by the applicant but must not be less than VEF plus the
speed gained with the critical engine inoperative during the time
interval between the instant at which the critical engine is failed and
the instant at which the pilot recognizes and reacts to the engine
failure, as indicated by the pilot's application of the first retarding
means during the accelerate-stop determination of Sec. 23.55.
(2) The rotation speed, VR, in terms of calibrated airspeed,
must be selected by the applicant and must not be less than the
greatest of the following:
(i) V1;
(ii) 1.05 VMC determined under Sec. 23.149(b);
(iii) 1.10 VS1; or
(iv) The speed that allows attaining the initial climb-out speed,
V2, before reaching a height of 35 feet above the takeoff surface
in accordance with Sec. 23.57(c)(2).
(3) For any given set of conditions, such as weight, altitude,
temperature, and configuration, a single value of VR must be used
to show compliance with both the one-engine-inoperative takeoff and
all-engines-operating takeoff requirements.
(4) The takeoff safety speed, V2, in terms of calibrated
airspeed, must be selected by the applicant so as to allow the gradient
of climb required in Sec. 23.67(c)(1) and (c)(2) but must not be less
than 1.10 VMC or less than 1.20 Vs1.
(5) The one-engine-inoperative takeoff distance, using a normal
rotation rate at a speed 5 knots less than VR, established in
accordance with paragraph (c)(2) of this section, must be shown not to
exceed the corresponding one-engine-inoperative takeoff distance,
determined in accordance with Sec. 23.57 and Sec. 23.59(a)(1), using
the established VR. The takeoff, otherwise performed in accordance
with Sec. 23.57, must be continued safely from the point at which the
airplane is 35 feet above the takeoff surface and at a speed not less
than the established V2 minus 5 knots.
(6) The applicant must show, with all engines operating, that
marked increases in the scheduled takeoff distances, determined in
accordance with Sec. 23.59(a)(2), do not result from over-rotation of
the airplane or out-of-trim conditions.
10. Section 23.53 is revised to read as follows:
Sec. 23.53 Takeoff performance.
(a) For normal, utility, and acrobatic category airplanes, the
takeoff distance must be determined in accordance with paragraph (b) of
this section, using speeds determined in accordance with Sec. 23.51(a)
and (b).
(b) For normal, utility, and acrobatic category airplanes, the
distance required to takeoff and climb to a height of 50 feet above the
takeoff surface must be determined for each weight, altitude, and
temperature within the operational limits established for takeoff
with--
(1) Takeoff power on each engine;
(2) Wing flaps in the takeoff position(s); and
(3) Landing gear extended.
(c) For commuter category airplanes, takeoff performance, as
required by Secs. 23.55 through 23.59, must be determined with the
operating engine(s) within approved operating limitations.
11. Section 23.55 is amended by revising paragraph (a) and the
introductory text of paragraph (b) to read as follows:
Sec. 23.55 Accelerate-stop distance.
* * * * *
(a) The accelerate-step distance is the sum of the distances
necessary to--
(1) Accelerate the airplane from a standing start to VEF with
all engines operating;
(2) Accelerate the airplane from VEF, to V1, assuming the
critical engine fails at VEF; and
(3) Come to a full stop from the point of which V1 is reached.
(b) Means other than wheel brakes may be used to determine the
accelerate-stop distances if that means--
* * * * *
12. Section 23.57 is amended by revising paragraphs (a)
introductory text, (b), (c)(1), (c)(3) introductory text, (c)(4), and
(d); and by adding a new paragraph (e) to read as follows:
Sec. 23.57 Takeoff path.
* * * * *
(a) The takeoff path extends from a standing start to a point in
the takeoff at which the airplane is 1500 feet above the takeoff
surface at or below which height the transition from the takeoff to the
enroute configuration must be completed; and
* * * * *
(b) During the acceleration to speed V2, the nose gear may be
raised off the ground at a speed not less than VR. However,
landing gear retraction must not be initiated until the airplane is
airborne.
(c) * * *
(1) The slope of the airborne part of the takeoff path must not be
negative at any point;
* * * * *
(3) At each point along the takeoff path, starting at the point at
which the airplane reaches 400 feet above the takeoff surface, the
available gradient of climb must not be less than--
* * * * *
(4) Except for gear retraction and automatic propeller feathering,
the airplane configuration must not be changed, and no change in power
that requires action by the pilot may be made, until the airplane is
400 feet above the takeoff surface.
(d) The takeoff path to 35 feet above the takeoff surface must be
determined by a continuous demonstrated takeoff.
(e) The takeoff flight path from 35 feet above the takeoff surface
must be determined by synthesis from segments; and
(1) The segments must be clearly defined and must be related to
distinct changes in configuration, power, and speed;
(2) The weight of the airplane, the configuration, and the power
must be assumed constant throughout each segment and must correspond to
the most critical condition prevailing in the segment; and
(3) The takeoff flight path must be based on the airplane's
performance without utilizing ground effect.
13. Section 23.59 is amended by revising the introductory text for
this section, paragraph (a)(2), and paragraph (b) to read as follows:
Sec. 23.59 Takeoff distance and takeoff run.
For each commuter category airplane, the takeoff distance and, at
the option of the applicant, the takeoff run, must be determined.
(a) * * *
(2) With all engines operating, 115 percent of the horizontal
distance from the start of the takeoff to the point at which the
airplane is 35 feet above the takeoff surface, determined by a
procedure consistent with Sec. 23.57.
(b) If the takeoff distance includes a clearway, the takeoff run is
the greater of--
(1) The horizontal distance along the takeoff path from the start
of the takeoff to a point equidistant between the liftoff point and the
point at which the airplane is 35 feet above the takeoff surface as
determined under Sec. 23.57; or
(2) With all engines operating, 115 percent of the horizontal
distance from the start of the takeoff to a point equidistant between
the liftoff point and the point at which the airplane is 35 feet above
the takeoff surface, determined by a procedure consistent with
Sec. 23.57.
14. A new Sec. 23.63 is added to read as follows:
Sec. 23.63 Climb: general.
(a) Compliance with the requirements of Secs. 23.65, 23.66, 23.67,
23.69, and 23.77 must be shown--
(1) Out of ground effect; and
(2) At speeds that are not less than those at which compliance with
the powerplant cooling requirements of Secs. 23.1041 to 23.1047 has
been demonstrated; and
(3) Unless otherwise specified, with one engine inoperative, at a
bank angle not exceeding 5 degrees.
(b) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of 6,000 pounds or less maximum weight,
compliance must be shown with Sec. 23.65(a), Sec. 23.67(a), where
appropriate, and Sec. 23.77(a) at maximum takeoff or landing weight, as
appropriate, in a standard atmosphere.
(c) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of more than 6,000 pounds maximum weight, and
turbine engine-powered airplanes in the normal, utility, and acrobatic
category, compliance must be shown at weights as a function of airport
altitude and ambient temperature, within the operational limits
established for takeoff and landing, respectively, with--
(1) Sections 23.65(b) and 23.67(b) (1) and (2), where appropriate,
for takeoff, and
(2) Section 23.67(b)(2), where appropriate, and Sec. 23.77(b), for
landing.
(d) For commuter category airplanes, compliance must be shown at
weights as a function of airport altitude and ambient temperature
within the operational limits established for takeoff and landing,
respectively, with--
(1) Sections 23.67(c)(1), 23.67(c)(2), and 23.67(c)(3) for takeoff;
and
(2) Sections 23.67(c)(3), 23.67(c)(4), and 23.77(c) for landing.
15. Section 23.65 is revised to read as follows:
Sec. 23.65 Climb: all engines operating.
(a) Each normal, utility, and acrobatic category reciprocating
engine-powered airplane of 6,000 pounds or less maximum weight must
have a steady climb gradient at sea level of at least 8.3 percent for
landplanes or 6.7 percent for seaplanes and amphibians with--
(1) Not more than maximum continuous power on each engine;
(2) The landing gear retracted;
(3) The wing flaps in the takeoff position(s); and
(4) A climb speed not less than the greater of 1.1 VMC and 1.2
VS1 for multiengine airplanes and not less than 1.2 VS1 for
single-engine airplanes.
(b) Each normal, utility, and acrobatic category reciprocating
engine-powered airplane of more than 6,000 pounds maximum weight and
turbine engine-powered airplanes in the normal, utility, and acrobatic
category must have a steady gradient of climb after takeoff of at least
4 percent with--
(1) Takeoff power on each engine;
(2) The landing gear extended, except that if the landing gear can
be retracted in not more than seven seconds, the test may be conducted
with the gear retracted;
(3) The wing flaps in the takeoff position(s); and
(4) A climb speed as specified in Sec. 23.65(a)(4).
16. A new Sec. 23.66 is added to read as follows:
Sec. 23.66 Takeoff climb: one-engine inoperative.
For normal, utility, and acrobatic category reciprocating engine-
powered airplanes of more than 6,000 pounds maximum weight, and turbine
engine-powered airplanes in the normal, utility, and acrobatic
category, the steady gradient of climb or descent must be determined at
each weight, altitude, and ambient temperature within the operational
limits established by the applicant with--
(a) The critical engine inoperative and its propeller in the
position it rapidly and automatically assumes;
(b) The remaining engine(s) at takeoff power;
(c) The landing gear extended, except that if the landing gear can
be retracted in not more than seven seconds, the test may be conducted
with the gear retracted;
(d) The wing flaps in the takeoff position(s);
(e) The wings level; and
(f) A climb speed equal to that achieved at 50 feet in the
demonstration of Sec. 23.53.
17. Section 23.67 is revised to read as follows:
Sec. 23.67 Climb: one engine inoperative.
(a) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of 6,000 pounds or less maximum weight, the
following apply:
(1) Except for those airplanes that meet the requirements
prescribed in Sec. 23.562(d), each airplane with a VSO of more
than 61 knots must be able to maintain a steady climb gradient of at
least 1.5 percent at a pressure altitude of 5,000 feet with the--
(i) Critical engine inoperative and its propeller in the minimum
drag position;
(ii) Remaining engine(s) at not more than maximum continuous power;
(iii) landing gear retracted;
(iv) Wing flaps retracted; and
(v) Climb speed not less than 1.2 VS1.
(2) For each airplane that meets the requirements prescribed in
Sec. 23.562(d), or that has a VSO of 61 knots or less, the steady
gradient of climb or descent at a pressure altitude of 5,000 feet must
be determined with the--
(i) Critical engine inoperative and its propeller in the minimum
drag position;
(ii) Remaining engine(s) at not more than maximum continuous power;
(iii) Landing gear retracted;
(iv) Wing flaps retracted; and
(v) Climb speed not less than 1.2 VS1.
(b) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of more than 6,000 pounds maximum weight, and
turbine engine-powered airplanes in the normal, utility, and acrobatic
category--
(1) The steady gradient of climb at an altitude of 400 feet above
the takeoff surface must be measurably positive with the--
(i) Critical engine inoperative and its propeller in the minimum
drag position;
(ii) Remaining engine(s) at takeoff power;
(iii) Landing gear retracted;
(iv) Wing flaps in the takeoff position(s); and
(v) Climb speed equal to that achieved at 50 feet in the
demonstration of Sec. 23.53.
(2) The steady gradient of climb must not be less than 0.75 percent
at an altitude of 1,500 feet above the takeoff surface, or landing
surface, as appropriate, with the--
(i) Critical engine inoperative and its propeller in the minimum
drag position;
(ii) Remaining engine(s) at not more than maximum continuous power;
(iii) Landing gear retracted;
(iv) Wing flaps retracted; and
(v) Climb speed not less than 1.2 VS1.
(c) For commuter category airplanes, the following apply:
(1) Takeoff; landing gear extended. The steady gradient of climb at
the altitude of the takeoff surface must be measurably positive for
two-engine airplanes, not less than 0.3 percent for three-engine
airplanes, or 0.5 percent for four-engine airplanes with--
(i) The critical engine inoperative and its propeller in the
position it rapidly and automatically assumes;
(ii) The remaining engine(s) at takeoff power;
(iii) The landing gear extended, and all landing gear doors open;
(iv) The wing flaps in the takeoff position(s);
(v) The wings level; and
(vi) A climb speed equal to V2.
(2) Takeoff; landing gear retracted. The steady gradient of climb
at an altitude of 400 feet above the takeoff surface must be not less
than 2.0 percent for two-engine airplanes, 2.3 percent for three-engine
airplanes, and 2.6 percent for four-engine airplanes with--
(i) The critical engine inoperative and its propeller in the
position it rapidly and automatically assumes;
(ii) The remaining engine(s) at takeoff power;
(iii) The landing gear retracted;
(iv) The wing flaps in the takeoff position(s);
(v) A climb speed equal to V2.
(3) Enroute. The steady gradient of climb at an altitude of 1,500
feet above the takeoff or landing surface, as appropriate, must be not
less than 1.2 percent for two-engine airplanes, 1.5 percent for three-
engine airplanes, and 1.7 percent for four-engine airplanes with--
(i) The critical engine inoperative and its propeller in the
minimum drag position;
(ii) The remaining engine(s) at not more than maximum continuous
power;
(iii) The landing gear retracted;
(iv) The wing flaps retracted; and
(v) A climb speed not less than 1.2 VS1.
(4) Discontinued approach. The steady gradient of climb at an
altitude of 400 feet above the landing surface must be not less than
2.1 percent for two-engine airplanes, 2.4 percent for three-engine
airplanes, and 2.7 percent for four-engine airplanes, with--
(i) The critical engine inoperative and its propeller in the
minimum drag position;
(ii) The remaining engine(s) at takeoff power;
(iii) Landing gear retracted;
(iv) Wing flaps in the approach position(s) in which VS1 for
these position(s) does not exceed 110 percent of the VS1 for the
related all-engines-operating landing position(s); and
(v) A climb speed established in connection with normal landing
procedures but not exceeding 1.5 VS1.
18. A new Sec. 23.69 is added to read as follows:
Sec. 23.69 Enroute climb/descent.
(a) All engines operating. The steady gradient and rate of climb
must be determined at each weight, altitude, and ambient temperature
within the operational limits established by the applicant with--
(1) Not more than maximum continuous power on each engine;
(2) The landing gear retracted;
(3) The wing flaps retracted; and
(4) A climb speed not less than 1.3 VS1.
(b) One engine inoperative. The steady gradient and rate of climb/
descent must be determined at each weight, altitude, and ambient
temperature within the operational limits established by the applicant
with--
(1) The critical engine inoperative and its propeller in the
minimum drag position;
(2) The remaining engine(s) at not more than maximum continuous
power;
(3) The landing gear retracted;
(4) The wing flaps retracted; and
(5) A climb speed not less than 1.2 VS1.
19. A new Sec. 23.71 is added to read as follows:
Sec. 23.71 Glide: Single-engine airplanes.
The maximum horizontal distance traveled in still air, in nautical
miles, per 1,000 feet of altitude lost in a glide, and the speed
necessary to achieve this must be determined with the engine
inoperative, its propeller in the minimum drag position, and landing
gear and wing flaps in the most favorable available position.
20. A new Sec. 23.73 is added to read as follows:
Sec. 23.73 Reference landing approach speed.
(a) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of 6,000 pounds or less maximum weight, the
reference landing approach speed, VREF, must not be less than the
greater of VMC, determined in Sec. 23.149(b) with the wing flaps
in the most extended takeoff position, and 1.3 VSO.
(b) For normal, utility, and acrobatic category reciprocating
engine-powered airplanes of 6,000 pounds maximum weight, and turbine
engine-powered airplanes in the normal, utility, and acrobatic
category, the reference landing approach speed, VREF, must not be
less than the greater of VMC, determined in Sec. 23.149(c), and
1.3 VSO.
(c) For commuter category airplanes, the reference landing approach
speed, VREF, must not be less than the greater of 1.05 VMC,
determined in Sec. 23.149(c), and 1.3 VSO.
21. Section 23.75 is amended by revising the section heading,
introductory text for the section; the introductory text of paragraph
(a); and paragraphs (b), (d), (e), and (f), and by removing paragraph
(h), to read as follows:
Sec. 23.75 Landing distance.
The horizontal distance necessary to land and come to a complete
stop from a point 50 feet above the landing surface must be determined,
for standard temperatures at each weight and altitude within the
operational limits established for landing, as follows:
(a) A steady approach at not less than VREF, determined in
accordance with Sec. 23.73 (a), (b), or (c), as appropriate, must be
maintained down to the 50 foot height and--
* * * * *
(b) A constant configuration must be maintained throughout the
maneuver.
* * * * *
(d) It must be shown that a safe transition to the balked landing
conditions of Sec. 23.77 can be made from the conditions that exist at
the 50 foot height, at maximum landing weight, or at the maximum
landing weight for altitude and temperature of Sec. 23.63(c)(2) or
(d)(2), as appropriate.
(e) The brakes must be used so as to not cause excessive wear of
brakes or tires.
(f) Retardation means other than wheel brakes may be used if that
means--
(1) Is safe and reliable; and
(2) Is used so that consistent results can be expected in service.
* * * * *
22. Section 23.77 is revised to read as follows:
Sec. 23.77 Balked landing.
(a) Each normal, utility, and acrobatic category reciprocating
engine-powered airplane of 6,000 pounds or less maximum weight must be
able to maintain a steady gradient of climb at sea level of at least
3.3 percent with--
(1) Takeoff power on each engine;
(2) The landing gear extended;
(3) The wing flaps in the landing position, except that if the
flaps may safely be retracted in two seconds or less without loss of
altitude and without sudden changes of angle of attack, they may be
retracted; and
(4) A climb speed equal to VREF, as defined in Sec. 23.73(a).
(b) Each normal, utility, and acrobatic category reciprocating
engine-powered airplane of more than 6,000 pounds maximum weight and
each normal, utility, and acrobatic category turbine engine-powered
airplane must be able to maintain a steady gradient of climb of at
least 2.5 percent with--
(1) Not more than the power that is available on each engine eight
seconds after initiation of movement of the power controls from minimum
flight-idle position;
(2) The landing gear extended;
(3) The wing flaps in the landing position; and
(4) A climb speed equal to VREF, as defined in Sec. 23.73(b).
(c) Each commuter category airplane must be able to maintain a
steady gradient of climb of at least 3.2 percent with--
(1) Not more than the power that is available on each engine eight
seconds after initiation of movement of the power controls from the
minimum flight idle position;
(2) Landing gear extended;
(3) Wing flaps in the landing position; and
(4) A climb speed equal to VREF, as defined in Sec. 23.73(c).
23. Section 23.143 is amended by revising paragraphs (a) and (c) to
read as follows:
Sec. 23.143 General.
(a) The airplane must be safely controllable and maneuverable
during all flight phases including--
(1) Takeoff;
(2) Climb;
(3) Level flight;
(4) Descent;
(5) Go-around; and
(6) Landing (power on and power off) with the wing flaps extended
and retracted.
* * * * *
(c) If marginal conditions exist with regard to required pilot
strength, the control forces required must be determined by
quantitative tests. In no case may the control forces under the
conditions specified in paragraphs (a) and (b) of this section exceed
those prescribed in the following table:
------------------------------------------------------------------------
Values in pounds force applied to the
relevant control Pitch Roll Yaw
------------------------------------------------------------------------
(a) For temporary application:
Stick...................................... 60 30
Wheel (Two hands on rim)................... 75 50
Wheel (One hand on rim).................... 50 25
Rudder Pedal............................... ....... ....... 150
(b) For prolonged application................ 10 5 20
------------------------------------------------------------------------
24. Section 23.145 is amended by revising paragraph (b)
introductory text, paragraphs (b)(2) through (b)(5); adding a new
paragraph (b)(6); and revising paragraphs (c) and (d) to read as
follows:
Sec. 23.145 Longitudinal control.
* * * * *
(b) Unless otherwise required, it must be possible to carry out the
following maneuvers without requiring the application of single-handed
control forces exceeding those specified in Sec. 23.143(c). The
trimming controls must not be adjusted during the maneuvers:
* * * * *
(2) With landing gear and flaps extended, power off, and the
airplane as nearly as possible in trim at 1.3 VSO, quickly apply
takeoff power and retract the flaps as rapidly as possible to the
recommended go around setting and allow the airspeed to transition from
1.3 VSO to 1.3 VS1. Retract the gear when a positive rate of
climb is established.
(3) With landing gear and flaps extended, in level flight, power
necessary to attain level flight at 1.1 VSO, and the airplane as
nearly as possible in trim, it must be possible to maintain
approximately level flight while retracting the flaps as rapidly as
possible with simultaneous application of not more than maximum
continuous power. If gated flap positions are provided, the flap
retraction may be demonstrated in stages with power and trim reset for
level flight at 1.1 VS1 in the initial configuration for each
stage--
(i) From the fully extended position to the most extended gated
position;
(ii) Between intermediate gated positions, if applicable; and
(iii) From the least extended gated position to the fully retracted
position.
(4) With power off, flaps and landing gear retracted and the
airplane as nearly as possible in trim at 1.4 VS1, apply takeoff
power rapidly while maintaining the same airspeed.
(5) With power off, landing gear and flaps extended, and the
airplane as nearly as possible in trim at VREF, obtain and
maintain airspeeds between 1.1. VSO and either 1.7 VSO or
VFE, whichever is lower without requiring the application of two-
handed control forces exceeding those specified in Sec. 23.143(c).
(6) With maximum takeoff power, landing gear retracted, flaps in
the takeoff position, and the airplane as nearly as possible in trim at
VFE appropriate to the takeoff flap position, retract the flaps as
rapidly as possible while maintaining constant speed.
(c) At speeds above VMO/MMO, and up to the maximum speed
shown under Sec. 23.251, a maneuvering capability of 1.5 g must be
demonstrated to provide a margin to recover from upset or inadvertent
speed increase.
(d) It must be possible, with a pilot control force of not more
than 10 pounds, to maintain a speed of not more than VREF during a
power-off glide with landing gear and wing flaps extended, for any
weight of the airplane, up to and including the maximum weight.
* * * * *
25. Section 23.147 is revised to read as follows:
Sec. 23.147 Directional and lateral control.
(a) For each multiengine airplane, it must be possible, while
holding the wings level within five degrees, to make sudden changes in
heading safely in both directions. This ability must be shown at 1.4
VS1 with heading changes up to 15 degrees, except that the heading
change at which the rudder force corresponds to the limits specified in
Sec. 23.143 need not be exceeded, with the--
(1) Critical engine inoperative and its propeller in the minimum
drag position;
(2) Remaining engines at maximum continuous power;
(3) Landing gear--
(i) Retracted; and
(ii) Extended; and
(4) Flaps retracted.
(b) For each multiengine airplane, it must be possible to regain
full control of the airplane without exceeding a bank angle of 45
degrees, reaching a dangerous attitude or encountering dangerous
characteristics, in the event of a sudden and complete failure of the
critical engine, making allowance for a delay of two seconds in the
initiation of recovery action appropriate to the situation, with the
airplane initially in trim, in the following conditions:
(1) Maximum continuous power on each engine;
(2) The wing flaps retracted;
(3) The landing gear retracted;
(4) A speed equal to that at which compliance with Sec. 23.69(a)
has been shown; and
(5) All propeller controls in the position at which compliance with
Sec. 23.69(a) has been shown.
(c) For all airplanes, it must be shown that the airplane is safely
controllable without the use of the primary lateral control system in
any all-engine configuration(s) and at any speed or altitude within the
approved operating envelope. It must also be shown that the airplane's
flight characteristics are not impaired below a level needed to permit
continued safe flight and the ability to maintain attitudes suitable
for a controlled landing without exceeding the operational and
structural limitations of the airplane. If a single failure of any one
connecting or transmitting link in the lateral control system would
also cause the loss of additional control system(s), the above
requirement is equally applicable with those additional systems also
assumed to be inoperative.
26. Section 23.149 is revised to read as follows:
Sec. 23.149 Minimum control speed.
(a) VMC is the calibrated airspeed at which, when the critical
engine is suddenly made inoperative, it is possible to maintain control
of the airplane with that engine still inoperative, and thereafter
maintain straight flight at the same speed with an angle of bank of not
more than 5 degrees. The method used to simulate critical engine
failure must represent the most critical mode of powerplant failure
with respect to controllability expected in service.
(b) VMC for takeoff must not exceed 1.2 VS1, where
VS1 is determined at the maximum takeoff weight. VMC must be
determined with the most unfavorable weight and center of gravity
position and with the airplane airborne and the ground effect
negligible, for the takeoff configuration(s) with--
(1) Maximum available takeoff power initially on each engine;
(2) The airplane trimmed for takeoff;
(3) Flaps in the takeoff position(s);
(4) Landing gear retracted; and
(5) All propeller controls in the recommended takeoff position
throughout.
(c) For all airplanes except reciprocating engine-powered airplanes
of 6,000 pounds or less maximum weight, the conditions of paragraph (a)
must also be met for the landing configuration with--
(1) Maximum available takeoff power initially on each engine;
(2) The airplane trimmed for an approach, with all engines
operating, at VREF, at an approach gradient equal to the steepest
used in the landing distance demonstration of Sec. 23.75;
(3) Flaps in the landing position;
(4) Landing gear extended; and
(5) All propeller controls in the position recommended for approach
with all engines operating.
(d) A minimum speed to intentionally render the critical engine
inoperative must be established and designated as the safe,
intentional, one-engine-inoperative speed, VSSE.
(e) At VMC, the rudder pedal force required to maintain
control must not exceed 150 pounds and it must not be necessary to
reduce power of the operative engine(s). During the maneuver, the
airplane must not assume any dangerous attitude and it must be possible
to prevent a heading change of more than 20 degrees.
(f) At the option of the applicant, to comply with the requirements
of Sec. 23.51(c)(1), VMCG may be determined. VMCG is the
minimum control speed on the ground, and is the calibrated airspeed
during the takeoff run at which, when the critical engine is suddenly
made inoperative, it is possible to maintain control of the airplane
using the rudder control alone (without the use of nosewheel steering),
as limited by 150 pounds of force, and using the lateral control to the
extent of keeping the wings level to enable the takeoff to be safely
continued. In the determination of VMCG, assuming that the path of
the airplane accelerating with all engines operating is along the
centerline of the runway, its path from the point at which the critical
engine is made inoperative to the point at which recovery to a
direction parallel to the centerline is completed may not deviate more
than 30 feet laterally from the centerline at any point. VMCG must
be established with--
(1) The airplane in each takeoff configuration or, at the option of
the applicant, in the most critical takeoff configuration;
(2) Maximum available takeoff power on the operating engines;
(3) The most unfavorable center of gravity;
(4) The airplane trimmed for takeoff; and
(5) The most unfavorable weight in the range of takeoff weights.
27. Section 23.153 is revised to read as follows:
Sec. 23.153 Control during landings.
It must be possible, while in the landing configuration, to safely
complete a landing without exceeding the one-hand control force limits
specified in Sec. 23.143(c) following an approach to land--
(a) At a speed of VREF minus 5 knots;
(b) With the airplane in trim, or as nearly as possible in trim and
without the trimming control being moved throughout the maneuver;
(c) At an approach gradient equal to the steepest used in the
landing distance demonstration of Sec. 23.75; and
(d) With only those power changes, if any, that would be made when
landing normally from an approach at VREF.
28. Section 23.155 is amended by revising the introductory text of
paragraph (b) and paragraph (b)(1), and by adding a new paragraph (c)
to read as follows:
Sec. 23.155 Elevator control force in maneuvers.
* * * * *
(b) The requirement of paragraph (a) of this section must be met at
75 percent of maximum continuous power for reciprocating engines, or
the maximum continuous power for turbine engines, and with the wing
flaps and landing gear retracted--
(1) In a turn, with the trim setting used for wings level flight at
VO; and
* * * * *
(c) There must be no excessive decrease in the gradient of the
curve of stick force versus maneuvering load factor with increasing
load factor.
29. Section 23.157 is amended by revising paragraph (d) to read as
follows:
Sec. 23.157 Rate of roll.
* * * * *
(d) The requirement of paragraph (c) of this section must be met
when rolling the airplane in each direction in the following
conditions--
(1) Flaps in the landing position(s);
(2) Land gear extended;
(3) All engines operating at the power for a 3 degree approach; and
(4) The airplane trimmed at VREF.
30. Section 23.161 is amended by revising paragraphs (a), (b)(1),
(b)(2), (c), the introductory text of paragraph (d), and (d)(4), and by
adding a new paragraph (e) to read as follows:
Sec. 23.161 Trim.
(a) General. Each airplane must meet the trim requirements of this
section after being trimmed and without further pressure upon, or
movement of, the primary controls or their corresponding trim controls
by the pilot or the automatic pilot. In addition, it must be possible,
in other conditions of loading, configuration, speed and power to
ensure that the pilot will not be unduly fatigued or distracted by the
need to apply residual control forces exceeding those for prolonged
application of Sec. 23.143(c). This applies in normal operation of the
airplane and, if applicable, to those conditions associated with the
failure of one engine for which performance characteristics are
established.
(b) * * *
(1) For normal, utility, and acrobatic category airplanes, at a
speed of 0.9 VH, VC, or VMO/MMO, whichever is
lowest; and
(2) For the commuter category airplanes, at all speeds from 1.4
VS1 to the lesser of VH or VMO/MMO.
(c) Longitudinal trim. The airplane must maintain longitudinal trim
under each of the following conditions:
(1) A climb with--
(i) Takeoff power, landing gear retracted, wing flaps in the
takeoff position(s), at the speeds used in determining the climb
performance required by Sec. 23.65; and
(ii) Maximum continuous power at the speeds and in the
configuration used in determining the climb performance required by
Sec. 23.69(a).
(2) Level flight at all speeds from the lesser of VH and
either VNO or VMO/MMO (as appropriate), to 1.4 VS1,
with the landing gear and flaps retracted.
(3) A descent at VNO or VMO/MMO, whichever is
applicable, with power off and with the landing gear and flaps
retracted.
(4) Approach with landing gear extended and with--
(i) A 3 degree angle of descent, with flaps retracted and at a
speed of 1.4 VS1;
(ii) A 3 degree angle of descent, flaps in the landing position(s)
at VREF; and
(iii) An approach gradient equal to the steepest used in the
landing distance demonstrations of Sec. 23.75, flaps in the landing
position(s) at VREF.
(d) In addition, each multiengine airplane must maintain
longitudinal and directional trim, and the lateral control force must
not exceed 5 pounds at the speed used in complying with Sec. 23.67(a),
(b)(2), or (c)(3), as appropriate, with--
* * * * *
(4) Wing flaps retracted; and
* * * * *
(e) In addition, each commuter category airplane for which, in the
determine of the takeoff path in accordance with Sec. 23.57, the climb
in the takeoff configuration at V2 extends beyond 400 feet above
the takeoff surface, it must be possible to reduce the longitudinal and
lateral control forces to 10 pounds and 5 pounds, respectively, and the
directional control force must not exceed 50 pounds at V2 with--
(1) The critical engine inoperative and its propeller in the
minimum drag position;
(2) The remaining engine(s) at takeoff power;
(3) Landing gear retracted;
(4) Wing flaps in the takeoff position(s); and
(5) An angle of bank not exceeding 5 degrees.
31. Section 23.175 is revised to read as follows:
Sec. 23.175 Demonstration of static longitudinal stability.
Static longitudinal stability must be shown as follows:
(a) Climb. The stick force curve must have a stable slope at speeds
between 85 and 115 percent of the trim speed, with--
(1) Flaps retracted;
(2) Landing gear retracted;
(3) Maximum continuous power; and
(4) The airplane trimmed at the speed used in determining the climb
performance required by Sec. 23.69(a).
(b) Cruise. With flaps and landing gear retracted and the airplane
in trim with power for level flight at representative cruising speeds
at high and low altitudes, including speeds up to VNO or VMO/
MMO, as appropriate, except that the speed need not exceed
VH--
(1) For normal, utility, and acrobatic category airplanes, the
stick force curve must have a stable slope at all speeds within a range
that is the greater of 15 percent of the trim speed plus the resulting
free return speed range, or 40 knots plus the resulting free return
speed range, above and below the trim speed, except that the slope need
not be stable--
(i) At speeds less than 1.3 VS1; or
(ii) For airplanes with VNE established under Sec. 23.1505(a),
at speeds greater than VNE; or
(iii) For airplanes with VMO/MMO established under
Sec. 23.1505(c), at speeds greater than VFC/MFC.
(2) For commuter category airplanes, the stick force curve must
have a stable slope at all speeds within a range of 50 knots plus the
resulting free return speed range, above and below the trim speed,
except that the slope need not be stable--
(i) At speeds less than 1.4 VS1; or
(ii) At speeds greater than VFC/M