[Federal Register Volume 60, Number 196 (Wednesday, October 11, 1995)]
[Proposed Rules]
[Pages 52872-52874]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25161]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-137-AD]


Airworthiness Directives; Airbus Model A310 and A300-600 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to all Airbus Model A310 and 
A300-600 series airplanes, that currently requires a revision to the 
FAA-approved Airplane Flight Manual (AFM) that warns the flight crew 
about certain consequences associated with overriding the autopilot 
while it is in the COMMAND mode or in the pitch axis. That AD also 
requires modification of certain flight control computers (FCC). This 
action would require replacement of the currently required revision to 
the AFM with a newly worded revision that explains the effect the 
modification of the FCC's has on the operation and performance of the 
autopilot and that clarifies the limitation for unmodified airplanes. 
This proposal is prompted by the results of an FAA review of the 
requirements of the existing AD. The actions specified by the proposed 
AD are intended to prevent an out-of-trim condition between the 
trimmable horizontal stabilizer and the elevator, which could severely 
reduce controllability of the airplane.

DATES: Comments must be received by November 20, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-137-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, Aerospace Engineer, 
Flight Test and Systems Branch, ANM-111, FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (206) 227-2315; fax (206) 227-1149.

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. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-137-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 95-NM-137-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On October 7, 1994, the FAA issued AD 94-21-07, amendment 39-9049 
(59 FR 52414, October 18, 1994), applicable to all Airbus Model A310 
and A300-600 series airplanes. That AD requires a revision to the 
Limitations Section of the FAA-approved Airplane Flight Manual (AFM) 
that warns the flight crew that overriding the autopilot while it is in 
the COMMAND mode could result in a severe out-of-trim condition, and 
that overriding the autopilot while it is in the pitch axis will not 
cancel the autotrim while it is in the ``land'' or ``go-around'' 
configuration. That AD also requires modification of certain flight 
control computers (FCC) so that the autopilot will disengage whenever 
the airplane is in the ``go-around'' mode above a certain airplane 
altitude. That action was prompted by an accident in which the flight 
crew may have attempted to override the autopilot while it was engaged 
in the COMMAND mode, which may have resulted in an out-of-trim 
condition between the trimmable horizontal stabilizer and the elevator. 
The requirements of that AD are intended to prevent this out-of-trim 
condition, which could result in severely reduced controllability of 
the airplane.
    Since the issuance of that AD, the FAA has conducted a review of 
the requirements of that AD, including the language contained in the 
required AFM limitation. The FAA finds that for airplanes on which 
modification of the FCC's has been accomplished, in accordance with the 
requirements of the existing AD, the language contained in the AFM 
limitation does not accurately reflect the operation and performance of 
the autopilot. Therefore, the FAA has determined that the language in 
the AFM limitation must be revised to state more clearly the effects 
the modification has on the operation and performance of the autopilot 
when the pilot attempts to override the autopilot by exerting a certain 
amount of manual force on the control column. Furthermore, the FAA 
finds that language contained in the AFM limitation required by that AD 
could be stated more clearly for airplanes on which modification of the 
FCC's has not been accomplished.
    The FAA has determined that these changes to the language of the 
AFM 

[[Page 52873]]
limitation are necessary to ensure that the flight crew is 
appropriately advised of (1) the potential hazard associated with 
overriding the autopilot under certain circumstances and with certain 
configurations of the FCC, and (2) the procedures necessary to address 
it.
    This airplane model is manufactured in France and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. The FAA has reviewed 
all available information, and determined that AD action is necessary 
for products of this type design that are certificated for operation in 
the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would supersede AD 94-21-07 to 
continue to require modification of certain FCC's. This action also 
requires replacement of the currently required revision to the 
Limitations Section of the FAA-approved AFM with a revised limitation. 
This revised limitation warns the flight crew that overriding the 
autopilot while it is in the COMMAND mode could result in a severe out-
of-trim condition, and that overriding the autopilot while it is in the 
pitch axis will not cancel the autotrim while it is in the ``land'' or 
``go-around'' configuration.
    This action also revises the language contained in the AFM 
limitation for airplanes on which the modification of the FCC's has 
been accomplished. It also clarifies the language contained in the AFM 
limitation for airplanes on which the modification of the FCC's has not 
been accomplished.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this long-standing requirement.
    There are approximately 15 Model A310 series airplanes and 36 Model 
A300-600 series airplanes of U.S. registry would be affected by this 
proposed AD.
    The modification that is currently required by AD 94-21-07 and 
retained in this proposal takes approximately 1 work hour per airplane 
to accomplish, at an average labor rate of $60 per work hour. Required 
parts will be supplied by the manufacturer at no cost to the operator. 
Based on these figures, the total cost impact on U.S. operators of the 
actions currently required is estimated to be $3,060, or $60 per 
airplane.
    The newly revised AFM limitation that is proposed in this AD action 
would take approximately 1 work hour per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts would be 
nominal in cost. Based on these figures, the total cost impact on U.S. 
operators of the proposed requirements of this AD is estimated to be 
$3,060, or $60 per airplane.
    The total cost impact figures discussed above are based on 
assumptions that no operator has yet accomplished any of the current or 
proposed requirements of this AD action, and that no operator would 
accomplish those actions in the future if this AD were not adopted.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 USC 106(g), 40101, 40113, 44701.


Sec. 39.13   [Amended]

    2. Section 39.13 is amended by removing amendment 39-9049 (59 FR 
52414, October 18, 1994), and by adding a new airworthiness directive 
(AD), to read as follows:

Airbus Industrie: Docket 95-NM-137-AD. Supersedes AD 94-21-07, 
Amendment 39-9049.

    Applicability: All Model A310 and A300-600 series airplanes, 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (d) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent an out-of-trim condition between the trimmable 
horizontal stabilizer and the elevator, which may severely reduce 
controllability of the airplane, accomplish the following:
    (a) Within 10 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the information contained in paragraph (a)(1) or 
(a)(2) of this AD, as applicable. This may be accomplished by 
inserting a copy of this AD in the AFM. The AFM limitation required 
by AD 94-21-07, amendment 39-9049, may be removed 

[[Page 52874]]
following accomplishment of the requirements of this paragraph.
    (1) For airplanes on which the flight control computers (FCC) 
have not been modified in accordance with the requirements of 
paragraph (b) of this AD:
    ``Overriding the autopilot (AP) in pitch axis does not cancel 
the AP autotrim when LAND TRACK mode [green LAND on both Flight Mode 
Annunciators (FMA)] or GO-AROUND mode is engaged. In these modes, if 
the pilot counteracts the AP, the autotrim will trim against pilot 
input. This could lead to a severe out-of-trim situation in a 
critical phase of flight.''
    (2) For airplanes on which the FCC's have been modified in 
accordance with requirements of paragraph (b) of this AD.
    ``Overriding the autopilot (AP) in pitch axis does not cancel 
the AP autotrim when LAND TRACK mode (green LAND on both FMA's) is 
engaged, or GO-AROUND mode is engaged below 400 feet radio altitude 
(RA). In these modes, if the pilot counteracts the AP, the autotrim 
will trim against pilot input. This could lead to a severe out-of-
trim situation in a critical phase of flight.''
    (b) For airplanes equipped with FCC's having either part number 
(P/N) B470ABM1 (for Model A310 series airplanes) or B470AAM1 (for 
Model A300-600 series airplanes): Within 60 days after November 2, 
1994 (the effective date of AD 94-21-07, amendment 39-9049), modify 
the FCC's in accordance with Airbus Service Bulletin A310-22-2036, 
dated December 14, 1993 (for Model A310 series airplanes), or Airbus 
Service Bulletin A300-22-6021, Revision 1, dated December 24, 1993 
(for Model A300-600 series airplanes), as applicable.

    Note 2: Paragraph (b) of this AD merely restates the 
requirements of paragraph (b) of AD 94-21-07, amendment 39-9049. As 
allowed by the phrase, ``unless accomplished previously,'' specified 
in the compliance statement of this AD, if those requirements of AD 
94-24-07 have already been accomplished, this AD does not require 
that those actions be repeated.

    (c) As of November 2, 1994 (the effective date of AD 94-21-07, 
amendment 39-9049), no person shall install an FCC having either P/N 
B470ABM1 or B470AAM1 on any airplane.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    Issued in Renton, Washington, on October 4, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-25161 Filed 10-10-95; 8:45 am]
BILLING CODE 4910-13-U