[Federal Register Volume 59, Number 200 (Tuesday, October 18, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-25581]


[[Page Unknown]]

[Federal Register: October 18, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-134-AD; Amendment 39-9049; AD 94-21-07]

 

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Airbus Model A310 and A300-600 series airplanes. 
This action requires a revision to the FAA-approved Airplane Flight 
Manual 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. This amendment also requires that certain 
flight control computers be modified so that the autopilot will 
disengage whenever the airplane is in the ``go-around'' mode. This 
amendment is 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 actions specified 
in this AD are intended to prevent severely reduced controllability of 
the airplane.

DATES: Effective November 2, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 2, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before December 19, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-134-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056.
    The service information referenced in this AD 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; or at the Office 
of the Federal Register, 800 North Capitol Street NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: The Direction Generale de l'Aviation Civile 
(DGAC), which is the airworthiness authority for France, recently 
notified the FAA that an unsafe condition may exist on all Airbus Model 
A310 and A300-600 series airplanes. The French DGAC advises that a 
Model A300-600 series airplane was recently involved in an accident 
during which the flight crew may have attempted a go-around while the 
airplane was in an out-of-trim condition. Investigation into the cause 
of this out-of-trim condition revealed that the flight crew may have 
attempted to override the autopilot while it was engaged in the COMMAND 
mode. If the airplane is in pitch axis, and the autopilot is overridden 
for prolonged periods by the flight crew via manual input from the 
control column, and if the autopilot is subsequently disengaged, the 
resultant out-of-trim condition between the trimmable horizontal 
stabilizer and the elevator could severely reduce controllability of 
the airplane.
    Further investigation indicates that the current design of Model 
A300-600 series airplanes does not provide for disengagement of the 
autopilot, which would allow for manual input from the control column 
without adversely affecting controllability of the airplane. The design 
of Model A310 series airplanes is identical in this respect to Model 
A300-600 series airplanes.
    Airbus has issued Service Bulletins A310-22-2036, dated December 
14, 1993 (for Model A310 series airplanes) and A300-22-6021, Revision 
1, dated December 24, 1993 (for Model A300-600 series airplanes), which 
describe procedures for modification of flight control computers (FCC) 
having part numbers (P/N) B470ABM1 (for Model A310 series airplanes) 
and B470AAM1 (for Model A300-600 series airplanes). Upon accomplishment 
of these software modifications, the autopilot will disengage whenever 
the airplane is in the ``go-around'' mode above 400 feet radio altitude 
and whenever the pilot attempts to override the autopilot by exerting a 
certain amount of manual force on the control column.
    The French DGAC classified these service bulletins as mandatory and 
issued French Airworthiness Directive 94-185-165(B), dated August 17, 
1994, in order to assure the continued airworthiness of these airplanes 
in France. The French AD requires modification of FCC's having P/N's 
B216ABM6, B350AAM1, B350AAM2, B350AAM3, and B470ABM1 (for Model A310 
series airplanes), and P/N B297AAM3, B297AAM4, B297AAM5, and B470AAM1 
(for Model A300-600 series airplanes), within 24 months after the 
effective date of the French AD.
    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. Pursuant to this 
bilateral airworthiness agreement, the French DGAC has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the French DGAC, 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, this AD is being issued to prevent an out-of-trim 
condition between the trimmable horizontal stabilizer and the elevator, 
which may severely reduce controllability of the airplane. This AD 
requires a revision to 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.
    This AD also requires modification of FCC's having P/N's B470ABM1 
(for Model A310 series airplanes) and B470AAM1 (for Model A300-600 
series airplanes) within 60 days after the effective date of the AD. In 
developing this compliance time, the FAA considered not only the degree 
of urgency associated with addressing the subject unsafe condition, but 
the availability of required parts and the practical aspect of 
installing the required modification within a maximum interval of time 
allowable for all affected airplanes to continue to operate without 
compromising safety. Since the manufacturer has advised that an ample 
number of required parts will be available for modification of these 
two part numbers, the FAA finds 60 days to be an appropriate compliance 
time for accomplishment of this modification. This modification is 
required to be accomplished in accordance with the accomplishment 
instructions contained in either of the applicable service bulletins 
described previously.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    The compliance time for accomplishment of the modification of FCC's 
having P/N's B216ABM6, B350AAM1, B350AAM2, and B350AAM3 (for Model A310 
series airplanes), and P/N's B297AAM3, B297AAM4, and B297AAM5 (for 
Model A300-600 series airplanes), is sufficiently long so that notice 
and public comment would not be impracticable. Therefore, the FAA is 
proposing to require modification of these FCC's in a separate 
rulemaking action (reference Airworthiness Directive Rules Docket 
Number 94-NM-145-AD). Since the manufacturer has not yet developed a 
modification for these FCC's, these modifications are proposed to be 
accomplished in accordance with a method approved by the FAA.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-134-AD.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-21-07 Airbus Industrie: Amendment 39-9049. Docket 94-NM-34-AD.

    Applicability: All Model A310 and A300-600 series airplanes; 
certificated in any category.
    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 following. This may be accomplished by 
inserting a copy of this AD in the AFM.
    Overriding the autopilot (AP) in the pitch axis does not cancel 
the AP autotrim in LAND and GO-AROUND modes. When the AP is in the 
COMMAND mode (CMD), if the pilot counteracts the AP, the AP will 
trim against the pilot input. This could lead to a severe out-of-
trim situation in a critical phase of flight.
    (b) For airplanes having flight control computer (FCC), part 
number (P/N) B470ABM1 (for Model A310 series airplanes) or B470AAM1 
(for Model A300-600 series airplanes): Within 60 days after the 
effective date of this AD, 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.
    (c) As of the effective date of this AD, no person shall install 
an FCC having 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. 
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 2: 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.
    (f) The modifications shall be done 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. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac 
Cedex, France. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or 
at the Office of the Federal Register, 800 North Capitol Street NW., 
suite 700, Washington, DC.
    (g) This amendment becomes effective on November 2, 1994.

    Issued in Renton, Washington, on October 7, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-25581 Filed 10-17-94; 8:45 am]
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