[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



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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.
---------------------------------------------------------------------------

    \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