[Federal Register Volume 59, Number 236 (Friday, December 9, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30219]
[[Page Unknown]]
[Federal Register: December 9, 1994]
_______________________________________________________________________
Part III
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
_______________________________________________________________________
14 CFR Parts 121, 125, and 135
Revision to Minimum Altitudes for Use of an Autopilot; Proposed Rules
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR parts 121, 125, and 135
[Docket No. 27987, Notice No. 94-34]
RIN 2120-AF19
Revision to Minimum Altitudes for the Use of an Autopilot
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The Federal Aviation Administration proposes to amend
regulations governing the use of approved flight control guidance
systems with automatic capability (autopilot). Current regulations
prohibit the use of an autopilot at altitudes less than 500 feet above
ground level (AGL) during the takeoff and initial climb phases of
flight. The proposed amendment would permit the use of approved
autopilot systems for takeoff and initial climb phases of flight if the
Administrator authorizes their use as stated in an air carrier's
operations specifications. By permitting air carriers to take advantage
of technological improvements in the operational capabilities of
autopilot systems, safety will be enhanced by decreasing pilot workload
during the critical takeoff phase of flight. This amendment is based on
a recommendation from the Aviation Rulemaking Advisory Committee
(ARAC).
DATES: Comments must be submitted on or before January 9, 1995.
ADDRESSES: Comments on this notice should be mailed, in triplicate, to:
Federal Aviation Administration, Office of the Chief Counsel,
Attention: Rules Docket (AGC-10), Docket No. 27987, 800 Independence
Avenue, SW., Washington, DC 20591. Comments delivered must be marked
Docket No. 27987. Comments may be examined in Room 915G weekdays
between 8:30 a.m. and 5:00 p.m., except on Federal holidays.
FOR FURTHER INFORMATION CONTACT: Richard A. Temple, AFS-410, Flight
Standards Service, Federal Aviation Administration, 800 Independence
Avenue, SW., Washington, DC 20591, telephone (202) 267-5824.
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,
federalism, 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 closing date for comments specified 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
substantive public contact with FAA personnel concerned with this
rulemaking 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. 27987.'' The
postcard will be date stamped and mailed to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the Federal Aviation Administration, Office of Public Affairs,
Attention: Public Inquiry Center, APA-220, 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
NPRMs should request from the above office a copy of Advisory Circular
(AC) No. 11-2A, Notice of Proposed Rulemaking Distribution System,
which describes the application procedure.
Background
Statement of the Problem
The FAA is proposing to amend Secs. 121.579, 125.329, and 135.93 of
the Federal Aviation Regulations (FAR) to permit certificate holders
that operate under parts 121, 125, or 135 to obtain authorization to
use an approved autopilot system for takeoff if authorized by the FAA
as stated in the certificate holder's operations specifications.
Section 121.579(a) currently states that no person may use an autopilot
en route, including climb and descent, at an altitude above the terrain
that is less than twice the maximum altitude loss specified in the
Airplane Flight Manual for a malfunction of the autopilot under cruise
conditions, or less than 500 feet, whichever is higher. Section
125.329(a) states that no person may use an autopilot at an altitude
above the terrain which is less than 500 feet or less than twice the
maximum altitude loss specified in the approved Airplane Flight Manual
or equivalent for a malfunction of the autopilot, whichever is higher.
Section 135.93(a) states that no person may use an autopilot at an
altitude above the terrain which is less than 500 feet or less than
twice the maximum altitude loss specified in the approved Airplane
Flight Manual or equivalent for a malfunction of the autopilot,
whichever is higher. Paragraphs (b) and (c) in Sec. 121.579, paragraphs
(b), (c) and (d) of Sec. 125.329, and paragraphs (b), (c), and (d) in
Sec. 135.93 provide exceptions to this restriction for the approach and
landing phases of flight. However, the regulations prohibit the use of
an autopilot system at altitudes below 500 feet AGL during the takeoff
and initial climb phases of flight under any condition.
The current restrictions in the regulations regarding the use of an
autopilot below 500 feet AGL have not been amended since 1965, when
provisions for the landing phase of flight were incorporated into
Sec. 121.579. This change was incorporated into part 135 when
Sec. 135.93 was recodified in 1978, and into part 125 when Sec. 125.329
was established in 1980. Although significant improvements in autopilot
technology have been made, the regulations have not been amended to
permit the use of an autopilot system during the takeoff and initial
climb phases of flight. In addition, the aviation industry anticipates
further improvements in autopilot technology, particularly in relation
to using the autopilot during the takeoff phase of flight.
The FAA proposes to amend Secs. 121.579, 125.329, and 135.93 in
this NPRM. The general discussion of the proposal is based, in part, on
developments of autopilots used in part 121 operations. However, the
autopilot technology, although used more widely by part 121 operators,
is always used by parts 125 and 135 operators. In addition, the intent
and safety considerations presented apply equally to parts 121, 125,
and 135 operations.
History of Sec. 121.579 of FAR
Part 121, Certification and Operations: Domestic, Flag, and
Supplemental Air Carriers and Commercial Operators of Large Aircraft,
Subpart T--Flight Operations, was recodified into the FAR in 1964 from
part 41 of the Civil Air Regulations. No substantive changes were made
to minimum altitude requirements for the use of autopilot systems at
that time.
The altitude restrictions of Sec. 121.579 established minimum
attitudes necessary to provide pilots with sufficient altitude for
obstacle clearance and the reaction time needed to disengage the
autopilot should a malfunction occur. An example of a particularly
critical malfunction is a ``hard-over.'' This malfunction may occur as
the result of an autopilot system failure where, for example, the
autopilot pitch control channel output commands a full nose-down
deflection of the pitch control surfaces of the airplane, resulting in
an abrupt change in the attitude of the airplane. Early autopilot
systems used by part 121 and other operators did not provide the system
redundancy and self-test features that automatically detect and
compensate for the failure of critical autopilot components and
preclude airplane flight control surface ``hard overs''. In the event
of such failures, pilots were required to disengage the autopilot and
manually manipulate the airplane flight controls to recover from the
effects of flight control hardovers. However, the capabilities of
autopilot systems have increased significantly; many autopilots are now
designed to detect all significant autopilot malfunctions and ensure
zero deviation from the intended flight path (including zero altitude
loss) in the event of autopilot malfunction.
The enhanced capabilities of autopilot systems and other flight
instrumentation have facilitated a reduction in minimum visibility
requirements for flight operations. In an effort to promote the
increased use of an all-weather landing system, the FAA amended
Sec. 121.579 to permit the use of an autopilot equipped with an
approach coupler, to touchdown, as approved in the air carrier's
operations specifications (Amendment 121-13, 30 FR 14781, November 22,
1965). This amendment facilitated the development of Category I, II,
and III instrument landing system (ILS). The use of these instrument
approach systems increased the safety of routine flight and landing
operations conducted in marginal weather. However, at the time the
regulation was amended, the aviation industry did not anticipate that
technological improvements would provide the ability to safely use an
autopilot system during the takoff and initial climb phases of flight.
As a result, the amendment addressed only the approach and landing
phases.
In March 1990, USAir petitioned the FAA for an exemption from
Sec. 121.579(a) of the FAR to allow the autopilot on USAir's Fokker 100
aircraft to be engaged during the takeoff phase of flight at an
altitude of 100 feet AGL (Exemption No. 5449, Docket No. 26218, 55 FR
31021, July 30, 1990). In response to the petition for exemption, the
FAA stated that it recognized the considerable improvements in the
reliability and performance of autopilot systems in recent years.
However, the FAA denied the petition on May 6, 1992, because USAir did
not provide the FAA with sufficient documentation verifying the FAA's
approval of that particular autopilot system. At that time, the FAA
decided that the ARAC should consider the issue and make
recommendations pertaining to regulatory changes.
The ARAC was chartered in February 1991 to provide recommendations
to the FAA Administrator, through the Associate Administrator for
Regulation and Certification and the Director of Rulemaking, on FAA
rulemaking activity related to aviation safety issues such as air
carrier operations. The ARAC Autopilot Engagement Requirements Working
Group was established to determine the criteria for autopilot
engagement and to address existing autopilot technology.
History of Sec. 125.329 of the FAR
On October 2, 1980, the FAA issued regulations establishing
certification and operations rules for large airplanes having a seating
capacity of 20 or more passengers or a maximum payload capacity of
6,000 pounds or more when used in other than common carriage.
[45FR67214] This rule was the outgrowth of an in-depth study of other
than common carriage charter operations using large airplanes. That
study began in 1970 at the direction of the Secretary of
Transportation. The authors of the study recommended that regulations
be developed for large airplanes, pressurized airplanes, and turbine-
powered airplanes engaged in other than common carriage. Some of the
requirements and restrictions formerly codified in parts 121 and 135
were also included in part 125 if they were deemed essential for safety
reasons; thus Sec. 125.329 was codified. Its purpose is to provide
passengers traveling on large airplanes operated in noncommon carriage
with a level of safety similar to that provided by parts 121 and 135
for purposes of autopilot requirements.
History of FAR Sec. 135.93
In 1978, part 135, Air Taxi Operators and Commercial Operators, was
substantially revised (43 FR 46783, October 10, 1978) and the
requirements of Sec. 121.579 concerning autopilot use were
substantially incorporated into Sec. 135.93. The purpose of the
revision was to provide passengers traveling on commuter air carrier or
on-demand air taxi flights with a level of safety similar to the level
of safety provided by part 121 operators. The amendment included minor
language revisions to improve the clarity of the regulation. No
significant changes have been made to the regulation since it as
adopted.
General Discussion of the Proposal
The ARAC and some industry members have expressed their opinion
that amending the regulation to permit increased usage of autopilot
engagement during takeoff would have certain benefits, such as allowing
pilots to focus proportionately more attention on duties other than the
manual manipulation of the flight controls and constant surveillance of
the cockpit instruments during the critical takeoff phase of flight.
Based on current autopilot technology, the expectation that technology
will continue to advance, and the safety benefits\1\ that would result
from using improved technology, the FAA has reevaluated the
restrictions of the current regulations and proposes to amend the
rules. The intent of the proposed rules is to permit authorization for
the use of an autopilot during the takeoff and initial climb phases of
flight; to enable part 121, 125, and 135 operators, when authorized, to
use existing technology; and to further promote technological advancers
while increasing the level of public safety.
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\1\See discussion under ``Safety Benefits.''
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Use of Autopilot Systems Below 500 Feet
Several transport category aircraft are currently equipped with
approved autopilot systems evaluated by the FAA during the aircraft
certification process to determine the minimum safe altitude
engagement, for operational use at altitudes below 500 feet AGL. These
autopilot systems are identified by make and model in the airplane
flight manual (AFM) and the minimum safe autopilot engagement altitude
for that particular make and model of autopilot is also stated in the
AFM. However, because of the restrictions in the applicable
regulations, AFM authorization alone does not permit such autopilots to
be used to the level of their demonstrated capability by certificate
holders operating under parts 121, 125, or 135. In proposing this
amendment, the FAA recognizes that airworthiness approval expressed in
an airplane's AFM is a prerequisite to permitting these autopilot
systems to be used during takeoff under the operating rules of parts
121, 125, and 135. Examples of transport category aircraft that have
autopilot systems identified in their AFMs that specify that such
autopilots may be engaged below 500 feet AGL include the Boeing 747-
400, approved for autopilot engagement at 250 feet AGL after takeoff;
the Boeing 757 and 767, approved for autopilot engagement at 200 feet
AGL; and the Fokker 100, approved for autopilot engagement at 400 feet
AGL. In order to obtain the certification, it was necessary for the
manufacturer to demonstrate low altitude engagement for the autopilot,
after takeoff, as safe and as part of the airworthiness certificate of
the particular system and autopilot on the airplane.
Further, European civil aviation authorities have approved the
engagement of particular autopilot systems on particular aircraft used
in air carrier operations at altitudes below 500 feet AGL during
takeoff. For example, the Dutch Ministry of Transport, Public Works and
Water Management. Airworthiness Division, Aeronautical Inspection
Directorate, approved the engagement of an Automatic Flight Control and
Augmentation System (AFCAS) in the Fokker 100 at 35 feet AGL during
takeoff.
Safety Benefits
In addition to permitting the use of autopilots with improved
capabilities, the proposed amendments to Secs. 121.579, 125.329, and
135.93, if adopted, would enhance public safety by decreasing pilot
workload during the critical takeoff phase of flight. As a practical
matter, this means that a pilot will spend less time manipulating the
controls and more time making other critical observations. Allowing the
engagement of an autopilot during the takeoff phase of flights would
enable the pilot to monitor the performance of the aircraft while
performing other critical functions, such as remaining alert to the
occurrence of airplane malfunctions and the presence of other aircraft
during takeoff. This is particularly important when the aircraft is in
the terminal area and exposed to more traffic. The pilot's ability to
devote more attention to the environment outside the cockpit supports
the ``see and avoid'' concept.
In addition, the use of an autopilot ensures consistent flight
maneuvers such as standardized climb profiles. Consistency in the
performance of such maneuvers enables the flight crew to more readily
identify any deviations from expected aircraft performance, thus
improving the pilot's opportunity to quickly compensate for the
deviation. Thus, since pilots may more readily identify problems and
may have more time to take action to compensate for deviations, the
level of safety should be increased.
Intent of the Proposal
The FAA and the aviation industry anticipate that further
technological advances will lead to the evolution of autoflight
guidance systems that can safely be used from initiation of takeoff
roll to completion of landing. Flexibility in the approval of minimum
engagement altitudes would allow the industry to work toward this goal
and at the same time would provide the authorization requirements
necessary to ensure that the industry meets or exceeds the level of
safety established by the current regulation.
Related Activity
If this proposal is adopted, the FAA plans to issue an advisory
circular (AC) in conjunction with the publication of the final rule.
The AC would provide guidelines for obtaining operational approval for
the use of an approved autopilot system during the takeoff phase of
flight. Approval would be based on the airworthiness approval of a
particular autopilot system installed on a particular airplane and on
the FAA's evaluation of the applicant's operational concepts, manuals,
and procedures; airborne equipment; airport and ground facilities used
in conjunction with the autopilot systems; flight crew training and
proficiency programs; and aircraft and equipment maintenance programs.
The operational aspects addressed in the AC would be similar to those
addressed in AC No. 120-28, Criteria for Approval of Category III
Landing Weather Minima (March 9, 1984), which provided guidance for
obtaining the approval of Category III landing weather minima by
amending the certificate holder's operations specifications, as
permitted by Sec. 121.579(c).
Proposed Amendment
Section 121.579
Section 121.579 would be amended by adding a new paragraph (d),
which would allow the Administrator to issue operations specifications
that establish the minimum altitude permitted to engage/use an
autopilot during the takeoff and initial climb phases of flight. In
addition, Sec. 121.579(a) would be amended by striking the words
``paragraphs (b) and (c)'' and inserting the words ``paragraphs (b),
(c), and (d).''
Section 125.329
Section 125.329 would be amended by adding paragraph (e) to allow
the Administrator to issue operations specifications that establish the
minimum altitude permitted to engage/use an autopilot during the
takeoff and initial climb phases of flight. In addition,
Sec. 125.329(a) would be amended by striking the words ``paragraphs
(b), (c), and (d)'' and inserting the words ``paragraphs (b), (c), (d),
and (e).''
Section 135.93
Section 135.93 would be amended by redesignating paragraph (e) as
paragraph (f) and adding a new paragraph (e) to allow the Administrator
to issue operations specifications that establish the minimum altitude
permitted to engage/use an autopilot during the takeoff and initial
climb phases of flight. In addition, Sec. 135.93(a) would be amended by
striking the words ``paragraphs (b), (c), and (d)'' and inserting the
words ``paragraphs (b), (c), (d), and (e).''
Paperwork Reduction Act
The information collection requirements in the proposed amendment
to Secs. 121.579, 125.329, and 135.93 have previously been approved by
the Office of Management and Budget (OMB) under the provisions of the
Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been
assigned OMB Control Number 2120-0008.
Economic Assessment
The FAA has determined that this rulemaking is not a significant
rulemaking action as defined by Executive Order 12866, and therefore no
assessment is required. In accordance with Department of Transportation
Policies and Procedures [44 FR 11034; February 26, 1979] when the
impact of the proposed regulation would be minimal if adopted, a full
regulatory evaluation does not need to be prepared. The following
discussion provides an economic assessment of the proposal's
anticipated costs and benefits.
Costs
The proposed amendment would allow air carriers and commercial
operators to seek authorization for the use of autopilot systems at
altitudes that would be prohibited under current regulations. Because
the decision whether to seek authorization for the use of autopilot is
optional, the proposed amendment would not impose any additional costs
on certificate holders that operate under parts 121, 125, or 135.
A certificate holder may obtain authorization to amend its
operations specifications to use an approved autopilot system provided
it is able to show that it either meets the guidelines in AC 120-AFGS
or an acceptable alternate means. Once authorization is given, the air
carrier or commercial operator would incur minimal training-related
costs. No significant additional pilot training would be required
because system usage and procedures training for use of the system
during the takeoff phase of flight is expected to mirror the current
training requirements for the use of the autopilot system for Category
I, II, and III instrument approaches. Completion of autopilot systems
training is currently documented in pilot training records. However, it
may be necessary to minimally modify pilot training programs and
related documentation to specifically address the use of the autopilot
system during the takeoff phase of flight. Furthermore, air carriers
and commercial operators are expected to have little if any additional
equipment costs because the autopilot equipment that would be used for
the takeoff phase of flight would, in most cases, be the same equipment
that is currently used to conduct Category I, II, and III approaches.
Benefits
This proposal would have only positive effects on the safety of air
operations. As with any change to operations specifications the FAA
would reserve the right to determine whether suggested revisions to an
air carrier's operations specifications meet the various criteria and
guidelines that would ensure that the current level of safety is met or
exceeded.
The use of the autopilot system below 500 feet AGL would enable the
pilot to monitor the performance of the aircraft while performing other
safety-related functions, such as scanning the outside area for other
aircraft. Since less time is spent manipulating the controls, the use
of the autopilot would also enable the flight crew to more readily
identify any deviations from expected aircraft performance thus
increasing the pilot's opportunity to quickly respond to any aircraft
malfunctions. Increasing the pilot's opportunity to scan the area
outside the aircraft for other airborne traffic, to detect aircraft
malfunctions, and to more quickly respond to problems will increase the
level of safety.
International Trade Impact Analysis
The FAA has determined that the proposed amendments to parts 121,
125, and 135, if adopted, would not have a significant impact on
international trade. The proposal is expected to have no negative
impact on trade opportunities for U.S. Firms doing business overseas or
foreign firms doing business in the United States.
International Civil Aviation Organization and Joint Aviation
Regulations
In keeping with U.S. obligations under the Convention on
International Civil Aviation, it is FAA policy to comply with ICAO
Standards and Recommended Practices (SARP) to the maximum extent
practicable. In reviewing the SARP for air carrier operations and JAR-
OPS 1, the FAA finds that there is not a comparable rule under either
ICAO standards or the JAR.
Regulatory Flexibility Deterimination
Congress enacted the Regulatory Flexibility Act (RFA) of 1980 (Pub.
L. 96-354) to ensure that small entities are not unnecessarily and
dispropriationately burdened by government regulations. The RFA
requires agencies to review proposed rules that may have a significant
impact on a substantial number of small entities. The proposed rule
would impose no additional costs on air carriers; therefore, it would
not have a significant economic impact on small business entities.
Federalism Implications
The regulations proposed herein would not have substantial direct
effects on the states, on the relationship between the national
government and the states, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient implications to warrant the
preparation of a Federalism Assessment.
Conclusion
For the reasons discussed in the preamble, and based on the
findings in the Regulatory Flexibility Determination and the
International Trade Impact Analysis, the FAA has determined that this
proposed regulation is not a significant rulemaking action under
Executive Order 12866. This proposed rule is also considered
nonsignificant under Department of Transportation Regulatory Policies
and Procedures [44FR11034; February 26, 1979] In addition, the FAA
certifies that this proposal, if adopted, would not have a significant
economic impact, positive or negative, on a substantial number of small
entities under the criteria of the RFA.
List of Subjects
14 CFR Part 121
Air carriers, Air transportation, Aircraft, Aircraft pilots,
Airmen, Airplanes, Airports, Airworthiness directives and standards,
Aviation safety, Pilots, Safety, Transportation.
14 CFR Part 125
Air carriers, Air transportation, Aircraft, Airmen, Airworthiness,
Aviation safety, Pilots, Safety.
14 CFR Part 135
Air carriers, Air transportation, Aircraft, Airmen, Airworthiness,
Aviation safety, Pilots, Safety.
The Proposed Amendment
In consideration of the foregoing, the Federal Aviation
Administration proposes to amend parts 121, 125, and 135 of the Federal
Aviation Regulations (14 CFR parts 121, 125, and 135) as follows:
PART 121--CERTIFICATION AND OPERATIONS: DOMESTIC, FLAG, AND
SUPPLEMENTAL AIR CARRIERS AND COMMERCIAL OPERATORS OF LARGE
AIRCRAFT
1. The authority citation for part 121 continues to read as
follows:
Authority: 49 U.S.C. app. 1354(a), 1355, 1356, 1357, 1401, 1421-
1430, 1472, 1485, and 1502; 49 U.S.C. 106(g).
2. Section 121.579 is amended by revising the phrase ``paragraph
(b) and (c)'' in paragraph (a) to read ``paragraph (b), (c), and (d)''
and adding new paragraph (d) to read as follows:
Sec. 121.579 Minimum altitudes for use of autopilot.
* * * * *
(d) Takeoffs. Notwithstanding paragraph (a) of this section, the
Administrator issues operations specifications to allow the use of an
approved autopilot system with automatic capability during the takeoff
and initial climb phase of flight provided:
(1) The system is not engaged prior to the minimum engagement
certification restriction specified in the Airplane Flight Manual; and
(2) The Administrator finds that the use of the system will not
otherwise affect the safety standards required by this section.
PART 125--CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING
CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF
6,000 POUNDS OR MORE
3. The authority citation for part 125 continues to read as
follows:
Authority: 49 U.S.C. app. 1354, 1421 through 1430, and 1502; 49
U.S.C. 106(g), Revised Pub. L. 97-449, January 12, 1983.
4. Section 125.329 is amended by revising the phrase ``paragraph
(b), (c), and (d)'' in paragraph (a) to read ``paragraph (b), (c), (d),
and (e)'' and adding new paragraph (e) to read as follows:
Sec. 125.329 Minimum altitudes for use of autopilot.
* * * * *
(e) Notwithstanding paragraph (a) of this section, the
Administrator issues operations specifications to allow the use of an
approved autopilot system with automatic capability during the takeoff
and initial climb phase of flight provided:
(1) The system is not engaged prior to the minimum engagement
certification restriction specified in the Airplane Flight Manual; and
(2) The Administrator finds that the use of the system will not
otherwise affect the safety standards required by this section.
PART 135--AIR TAXI OPERATORS AND COMMERCIAL OPERATORS
5. The authority citation for part 135 continues to read as
follows:
Authority: 49 U.S.C. app. 1354(a), 1355(a), 1421 through 1431,
and 1502; 49 U.S.C. 106(g).
6. Section 135.93 is amended by revising the phrase ``paragraph
(b), (c), and (d)'' in paragraph (a) to read ``paragraphs (b), (c),
(d), and (e),'' redesignating and republishing paragraph (e) as
paragraph (f), and adding new paragraph (e) to read as follows:
Sec. 135.93 Autopilot: Minimum altitudes for use.
* * * * *
(e) Notwithstanding paragraph (a) of this section, the
Administrator issues operations specifications to allow the use of an
approved autopilot system with automatic capability during the takeoff
and initial climb phase of flight provided:
(1) The system is not engaged prior to the minimum engagement
certification restriction specified in the Airplane Flight Manual; and
(2) The Administrator finds that the use of the system will not
otherwise affect the safety standards required by this section.
(f) This section does not apply to operations conducted in
rotorcraft.
Issued in Washington, D.C., on December 2, 1994.
Thomas C. Accardi,
Director, Flight Standards Service.
Subject: Criteria for Operational Approval of Auto Flight Guidance
Systems (AFGS)
1. Purpose
This advisory circular (AC) states an acceptable means, but not the
only means, for obtaining operational approval of the initial
engagement or use of an Auto Flight Guidance System (AFGS).
2. Applicability
The criteria contained in this AC are applicable to operators using
commercial turbojet and turboprop aircraft holding Federal Aviation
Administrations (FAA) operating authority issued under Parts 121, 125,
and 135 of the Federal Aviation Regulations (FAR). The FAA may approve
the AFGS operation for those operators, where necessary, by amending
the applicant's operations specifications (OPSPECS).
3. Background
a. There are now exceptions to the general regulations prohibiting
the use of autopilots at altitudes less than 500 feet above ground
level during the takeoff and climb phases of flight. This AC provides
guidance to certificate holders seeking FAA operational approval of the
initial engagement or use of an AFGS in order to take advantage of
technological improvements in the operational capabilities of autopilot
systems, particularly at lower altitudes. This AC complements a rule
change that would allow the use of an autopilot, certificated and
operationally approved by the FAA, at altitudes less than 500 feet
above ground level in the vertical plane and in accordance with
Sections 121.189(d)(2) or 135.367(a)(3) of the FAR, in the lateral
plane.
4. Definitions
Airplane Flight Manual (AFM)--A document (under Section 25.1581 of
the FAR) which is used to obtain an FAA type certificate. This document
contains the operating procedures and limitations and performance
information applicable to a particular airplane type in order to safely
operate that aircraft and conform to the type certificate.
Autopilot--An aircraft system and associated sensors designed to
provide automatic control of the pitch, roll and in certain instances,
yaw axis of an aircraft.
Auto Flight Guidance System (AFGS)--Aircraft systems, such as an
autopilot, autothrottles, displays, and controls, that are
interconnected in such a manner to allow the crew to automatically
control the aircraft's lateral and vertical flight path and speed. A
flight management system (FMS) is sometimes associated with an AFGS.
Auto Throttle System (ATS)--A system selected by the crew to
provide automatic engine thrust control, as required, to achieve and
maintain desired aircraft speed or vertical flight profile.
Control Wheel Steering (CWS)--A selectable feature of some
autopilots that directly relates control wheel displacement to a
desired aircraft response. The pilot's force or displacement inputs of
the control wheel/column or stick are transmitted by the autopilot into
appropriate commands to the control surfaces to achieve the desired
aircraft pitch, roll, or yaw response.
Flight Director (FD)--An instrument display system providing visual
commands for aircraft control by displaying appropriate command
indications on the primary flight display. The flight crew use these
command indications to manually fly the aircraft or monitor the
autopilot.
Flight Management Systems (FMS)--An integrated system used by
flight crews for flight planning, navigation, performance management,
aircraft guidance and flight progress monitoring.
Minimum Altitude for AFGS Engagement--Unless otherwise specified by
the FAA, the minimum height relevant to certain factors including the
airport elevation and runway elevation over which the crew may either
initially engage an AFGS for automatic flight after takeoff or allow
the AFGS to remain engaged during approach and landing.
5. Discussion
a. AFGS capabilities have steadily increased and improved with
time. Flight crews now routinely use autoflight features that are
operational during takeoff and landing/roll-out (e.g. control wheel
steering, automatic landing, automatic throttles, and wing-load
alleviation).
b. Some aircraft now have automatic features identified for
operations specifically at low altitudes (e.g. for noise abatement)
which when used, contribute to performance, workload, cost, noise, and
safety benefits. Such features are certificated on the aircraft by
either type certification or supplemental type certification. Operators
may obtain operational approval for service use by following the
guidance in this AC. This guidance should meet the intent of Section
121.579, 125.329, and 135.93 of the FAR for operational approval for
existing aircraft and describe acceptable methods for demonstration of
these systems for new or modified aircraft.
c. Initial engagement of the AFGS at the altitude specified in the
Airplane Flight Manual (AFM) may be authorized upon approval by the
principal operations inspector (POI) for the certificate holder. POI's
would revise the appropriate section of the operations specifications
(OPSPECS). The expectation is that as technology continues to advance,
additional operational and safety benefits can be derived from using
improved autopilot technology. Such a benefit may eventually include
the use of an AFGS from the beginning of the takeoff phase of flight.
6. Operational Concept
a. The AFGS, as discussed in this AC, consists of an Autopilot
(pitch, roll, and yaw) Flight Guidance System, that if used in
conjunction with other available components such as FMS, autothrottle,
etc., will enhance safety and ease pilot workload. Any or all of the
many available automatic operational features are selectable at the
pilot's discretion in modern transport aircraft. This allows a clear
distinction to be made in contrast to the primary flight control system
that may also be largely automatic and electronic but is not normally
deselectable at the crew's discretion, e.g. such as the yaw dampners.
b. There are several functions of an AFGS that could be presented
for operational approval. These functions could be used singularly or
in combination with each other. They may be operationally approved by
the Administrator through the certificate holder's training and
maintenance programs. The following are examples of these functions:
(1) Setting takeoff thrust
(2) Initial climb
(3) Noise abatement profiles
(4) Engine failure recognition
c. Operational approval for use of the above functions may include
the following:
--Airborne equipment
--Ground equipment
--Maintenance
Training
Equipment requirement
--Flight operations
Training
Operating procedures
7. Airport and Ground Facilities
An applicant authorized to use an AFGS may have certain constraints
related to airports or ground facilities specified in the operators
OPSPECS where such specific provisions are necessary (e.g. operations
based on special procedures at airports with adjacent mountains
terrain, operations requiring runway guidance information, etc.).
8. Airborne equipment
AFGS system criteria will be defined in the AFM.
9. Pilot Training and Proficiency Program
The operator's training program for flight crewmembers should
provide training in the following subjects:
a. Airport and ground facilities--as defined in the airborne
equipment certification, AFM, and OPSPECS.
b. Flight training program:
(1) For pilot certification/type rating requirements [appendix E,
part 121; subpart I, part 125; subpart H, part 135]:
(i) Training should demonstrate the ability and limits of operation
of the AFGS to the level of performance indicated by the AFM. This
includes all normal and abnormal procedures.
(ii) The pilot applicant should demonstrate to a satisfactory level
of performance the use of the AFGS within the allowable parameters
indicated by the AFM. Performance criteria should include all normal
and abnormal procedures.
(2) Pilot training for AFGS operations should be conducted in
accordance with Parts 121, 125, and 135 of the FAR.
(i) Pilot ground and flight training in the use of the AFGS, to
establish minima criteria for weather operations, will be authorized
through OPSPECS.
(ii) Pilot checking for initial authorization and at prescribed
recurrent intervals for each air carrier should be established.
Demonstration of normal and abnormal procedures should be included.
10. Operations Manual and Procedures
Procedures, instructions, and information to be used in flight
crews should be developed by each air carrier to include, as
applicable, the following:
a. Flight crewmember duties. Flight crewmember duties during
initial engagement or use of the AFGS should be described in the
operations manual. These duties should contain a description of the
responsibilities and tasks for the pilot flying the aircraft and the
pilot not flying the aircraft during all stages of operation. The
duties of the third flight crewmember, if required, should also be
defined.
b. Training information. Approved training requirements and
procedures should be provided in the operator's manual or available to
flight crews in an equivalent form for reference use.
11. Maintenance Program
Each operator should establish a maintenance and reliability
program, acceptable to the Administrator, to ensure that the airborne
equipment will continue at a level of performance and reliability
established by the manufacturer or the FAA. [subpart L, part 121;
subpart G, part 125; subpart J, part 135] The FAA would accept a
program that had the following elements:
a. Maintenance personnel training. Each operator should establish
an initial and recurrent training program, or arrange for contract
maintenance that is acceptable to the Administrator, for personnel
performing maintenance work on airborne systems and equipment.
Personnel training records should be maintained.
b. Test equipment and standard. The operator's program for
maintenance of line (ramp) test equipment, shop (bench) test equipment,
and a listing of all primary and secondary standards utilized during
maintenance of test equipment which relates to airborne system
operation should be submitted to the Administrator for determination of
adequacy. Emphasis should be placed on standards associated with flight
directors, automatic flight control systems, maintenance techniques and
procedures of associated redundant systems.
c. Maintenance procedures. Any changes to maintenance procedures,
practices, or limitations established in the qualification for airborne
system operations should be submitted to the Administrator for
acceptance before such changes are adopted.
12. Engineering Modifications
Titles and numbers of all modifications, additions, and changes
that were made to qualify aircraft systems performance should be
provided to the Administrator. [subparts D and E, part 21]
Subject: Criteria for Operational Approval of Auto Flight Guidance
Systems (AFGS)
1. Purpose
This advisory circular (AC) states an acceptable means, but not the
only means, for obtaining operational approval of the initial
engagement or use of an Auto Flight Guidance System (AFGS).
2. Applicability
The criteria contained in this AC are applicable to operators using
commercial turbojet and turboprop aircraft holding Federal Aviation
Administrations (FAA) operating authority issued under Parts 121, 125,
and 135 of the Federal Aviation Regulations (FAR). The FAA may approve
the AFGS operation for those operators, where necessary, by amending
the applicant's operations specifications (OPSPECS).
3. Background
a. There are now exceptions to the general regulations prohibiting
the use of autopilots at altitudes less than 500 feet above ground
level during the takeoff and climb phases of flight. This AC provides
guidance to certificate holders seeking FAA operational approval of the
initial engagement or use of an AFGS in order to take advantage of
technological improvements in the operational capabilities of autopilot
systems, particularly at lower altitudes. This AC complements a rule
change that would allow the use of an autopilot, certificated and
operationally approved by the FAA, at altitudes less than 500 feet
above ground level in the vertical plane and in accordance with
Sections 121.189(d)(2) or 135.367(a)(3) of the FAR, in the lateral
plane.
4. Definitions
Airplane Flight Manual (AFM)--A document (under Section 25.1581 of
the FAR) which is used to obtain an FAA type certificate. This document
contains the operating procedures and limitations and performance
information applicable to a particular airplane type in order to safely
operate that aircraft and conform to the type certificate.
Autopilot--An aircraft system and associated sensors designed to
provide automatic control of the pitch, roll and in certain instances,
yaw axis of an aircraft.
Auto Flight Guidance System (AFGS)--Aircraft systems, such as an
autopilot, autothrottles, displays, and controls, that are
interconnected in such a manner to allow the crew to automatically
control the aircraft's lateral and vertical flight path and speed. A
flight management system (FMA) is sometimes
Auto Throttle System (ATS)--A system selected by the crew to
provide automatic engine thrust control, as required, to achieve and
maintain desired aircraft speed or vertical flight profile.
Control Wheel Steering (CWS)--A selectable feature of some
autopilots that directly relates control wheel displacement to a
desired aircraft response. The pilot's force or displacement inputs of
the control wheel/column or stick are transmitted by the autopilot into
appropriate commands to the control surfaces to achieve the desired
aircraft pitch, roll, or yaw response.
Flight Director (FD)--An instrument display system providing visual
commands for aircraft control by displaying appropriate command
indications on the primary flight display. The flight crew use these
command indications to manually fly the aircraft or monitor the
autopilot.
Flight Management Systems (FMS)--An integrated system used by
flight crews for flight planning, navigation, performance management,
aircraft guidance and flight progress monitoring.
Minimum Altitude for AFGS Engagement--Unless otherwise specified by
the FAA, the minimum height relevant to certain factors including the
airport elevation and runway elevation over which the crew may either
initially engage an AFGS for automatic flight after takeoff or allow
the AFGS to remain engaged during approach and landing.
5. Discussion
a. AFGS capabilities have steadily increased and improved with
time. Flight crews now routinely use autoflight features that are
operational during takeoff and landing/roll-out (e.g. control wheel
steering, automatic landing, automatic throttles, and wing-load
alleviation).
b. Some aircraft now have automatic features identified for
operations specifically at low altitudes (e.g. for noise abatement)
which when used, contribute to performance, workload, cost, noise, and
safety benefits. Such features are certificated on the aircraft by
either type certification or supplemental type certification. Operators
may obtain operational approval for in service use by following the
guidance in this AC. This guidance should meet the intent of Section
121.579, 125.329, and 135.93 of the FAR for operational approval for
existing aircraft and describe acceptable methods for demonstration of
these systems for new or modified aircraft.
c. Initial engagement of the AFGS at the altitude specified in the
Airplane Flight Manual (AFM) may be authorized upon approval by the
principal operations inspector (POI) for the certificate holder. POI's
would revise the appropriate section of the operations specifications
(OPSPECS). The expectation is that as technology continues to advance,
additional operational and safety benefits can be derived from using
improved autopilot technology. Such a benefit may eventually include
the use of an AFGS from the beginning of the takeoff phase of flight.
6. Operational Concept
a. The AFGS, as discussed in this AC, consists of an Autopilot
(pitch, roll, and yaw) Flight Guidance System, that if used in
conjunction with other available components such as FMS, autothrottle,
etc., will enhance safety and ease pilot workload. Any or all of the
many available automatic operational features are selectable at the
pilot's discretion in modern transport aircraft. This allows a clear
distinction to be made in contrast to the primary flight control system
that may also be largely automatic and electronic but is not normally
deselectable at the crew's discretion, e.g. such as the yaw dampners.
b. There are several functions of an AFGS that could be presented
for operational approval. These functions could be used singularly or
in combination with each other. They may be operationally approved by
the Administrator through the certificate holder's training and
maintenance programs. The following are examples of these functions:
(1) Setting takeoff thrust
(2) Initial climb
(3) Noise abatement profiles
(4) Engine failure recognition
c. Operational approval for use of the above functions may include
the following:
--Airborne equipment
--Ground equipment
--Maintenance
Training
Equipment requirement
--Flight operations
Training
Operating procedures
7. Airport and Ground Facilities
An applicant authorized to use an AFGS may have certain constraints
related to airports or ground facilities specified in the operators
OPSPECS where such specific provisions are necessary (e.g. operations
based on special procedures at airports with adjacent mountainous
terrain, operations requiring runway guidance information, etc.).
8. Airborne Equipment
AFGS system criteria will be defined in the AFM.
9. Pilot Training and Proficiency Program
The operator's training program for flight crewmembers should
provide training in the following subjects:
a. Airport and ground facilities--as defined in the airborne
equipment certification, AFM, and OPSPECS.
b. Flight training program:
(1) For pilot certification/type rating requirements [appendix E,
part 121; subpart I, part 125; subpart H, part 135]:
(i) Training should demonstrate the ability and limits of operation
of the AFGS to the level of performance indicated by the AFM. This
includes all normal and abnormal procedures.
(ii) The pilot applicant should demonstrate to a satisfactory level
of performance the use of the AFGS within the allowable parameters
indicated by the AFM. Performance criteria should include all normal
and abnormal procedures.
(2) Pilot training for AFGS operations should be conducted in
accordance with Parts 121, 125, and 135 of the FAR.
(i) Pilot ground and flight training in the use of the AFGS, to
established minima criteria for weather operations, will be authorized
through OPSPECS.
(ii) Pilot checking for initial authorization and at prescribed
recurrent intervals for each air carrier should be established.
Demonstration of normal and abnormal procedures should be included.
10. Operations Manual and Procedures
Procedures, instructions, and information to be used by flight
crews should be developed by each air carrier to include, as
applicable, the following:
a. Flight crewmember duties. Flight crewmember duties during
initial engagement or use of the AFGS should be described in the
operations manual. These duties should contain a description of the
responsibilities and tasks for the pilot flying the aircraft and the
pilot not flying the aircraft during all stages of operation. The
duties of the third flight crewmember, if required, should also be
defined.
b. Training information. Approved training requirements and
procedures should be provided in the operator's manual or available to
flight crews in an equivalent form for reference use.
11. Maintenance Program
Each operator should establish a maintenance and reliability
program, acceptable to the Administrator, to ensure that the airborne
equipment will continue at a level of performance and reliability
established by the manufacturer or the FAA. [subpart L, part 121;
subpart G, part 125; subpart J, part 135] The FAA would accept a
program that had the following elements:
a. Maintenance personnel training. Each operator should establish
an initial and recurrent training program, or arrange for contract
maintenance that is acceptable to the Administrator, for personnel
performing maintenance work on airborne systems and equipment.
Personnel training records should be maintained.
b. Test equipment and standards. The operator's program for
maintenance of line (ramp) test equipment, shop (bench) test equipment,
and a listing of all primary and secondary standards utilized during
maintenance of test equipment which relates to airborne system
operation should be submitted to the Administrator for determination of
adequacy. Emphasis should be placed on standards associated with flight
directors, automatic flight control systems, maintenance techniques and
procedures of associated redundant systems.
c. Maintenance procedures. Any changes to maintenance procedures,
practices, or limitations established in the qualification for airborne
system operations should be submitted to the Administrator for
acceptance before such changes are adopted.
12. Engineering Modifications
Titles and numbers of all modifications, additions, and changes
that were made to qualify aircraft systems performance should be
provided to the Administrator. [subparts D and E, part 21]
[FR Doc. 94-30219 Filed 12-8-94; 8:45 am]
BILLING CODE 4910-13-M