[Federal Register Volume 62, Number 229 (Friday, November 28, 1997)]
[Proposed Rules]
[Pages 63296-63298]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-31158]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-188-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Airbus Model A300, A310, and 
A300-600 series airplanes. For certain airplanes, this proposal would 
require replacing the bearings of the throttle control levers with new 
sealed bearings. For certain other airplanes, this proposal would 
require replacing the throttle control assemblies with new assemblies. 
This proposal is prompted by the issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The actions specified by the proposed AD are intended to prevent 
asymmetric engine thrust on the airplane when the autothrottle is 
engaged, which could result in roll and yaw disturbances, and 
consequent reduced controllability of the airplane.

DATES: Comments must be received by December 29, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-188-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: International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4556, telephone (425) 227-2110; fax (425) 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 97-NM-188-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. 97-NM-188-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

[[Page 63297]]

Discussion

    The Direction Generale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, notified the FAA that an unsafe 
condition may exist on all Airbus Model A300, A310, and A300-600 series 
airplanes. The DGAC advises that it received reports indicating that 
the throttle control levers were difficult to move. This excessive 
friction or seizure of throttle control levers has been attributed to 
lack of lubrication and dust contamination of the bearings. In the case 
of airplanes equipped with full authority digital engine control 
(FADEC), this condition can also be attributed to excessive roller 
wear. These conditions could lead to asymmetric throttle movements and 
engine thrust when the autothrottle is engaged. Such asymmetric 
movements, if not corrected, could result in roll and yaw disturbances, 
and consequent reduced controllability of the airplane.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A300-76-0018, dated October 12, 
1995, as revised by Change Notice O.A., dated February 18, 1997 (for 
Model A300 series airplanes); and Service Bulletin A300-76-6010, dated 
October 12, 1995, as revised by Change Notice O.A., dated February 18, 
1997 (for Model A300-600 series airplanes); and Service Bulletin A310-
76-2013, dated October 12, 1995, as revised by Change Notice O.A., 
dated February 18, 1997 (for Model A310 series airplanes). These 
service bulletins describe procedures for replacement of the four 
bearings located on both throttle control levers with new sealed 
bearings. Replacement of these bearings will ensure a smooth and 
consistent operation of both throttles.
    Airbus also has issued Service Bulletin A310-76-2014, Revision 2, 
dated January 6, 1997 (for Model A310 series airplanes); and Service 
Bulletin A300-76-6011, Revision 2, dated January 6, 1997 (for Model 
A300-600 series airplanes). These service bulletins describe procedures 
for replacement of two throttle control assemblies equipped with 
rollers with new throttle control assemblies equipped with bearings. 
Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition.
    The DGAC classified these service bulletins as mandatory and issued 
French airworthiness directive (C/N) 96-270-209 (B), dated November 20, 
1996, in order to assure the continued airworthiness of these airplanes 
in France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 DGAC has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the 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.

Explanation of Requirements of Proposed Rule

    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 require accomplishment of 
the actions specified in the service bulletins described previously.

Cost Impact

    The FAA estimates that 66 airplanes of U.S. registry would be 
affected by this proposed AD.
    The FAA estimates that the proposed replacement of the bearings 
would be required to be accomplished on 57 airplanes. It would take 
approximately 24 work hours per airplane to accomplish that action, at 
an average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the replacement of the bearings 
proposed by this AD on U.S. operators is estimated to be $82,080, or 
$1,440 per airplane.
    The FAA estimates that the proposed replacement of the throttle 
support assemblies would be required to be accomplished on 9 airplanes. 
It would take approximately 28 work hours per airplane to accomplish 
that action, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $1,138 per airplane. Based on these 
figures, the cost impact of the replacement of the throttle support 
assemblies proposed by this AD on U.S. operators is estimated to be 
$25,362, or $2,818 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    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 ``Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-188-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.''

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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

Airbus Industrie: Docket 97-NM-188-AD.

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

    Note 1: This AD applies to each airplane identified in the 
preceding

[[Page 63298]]

applicability provision, regardless of whether it has been otherwise 
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 request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent asymmetric engine thrust on the airplane when the 
autothrottle is engaged, which could result in roll and yaw 
disturbances, and consequent reduced controllability of the 
airplane, accomplish the following:
    (a) Within 18 months or 3,500 flight hours after the effective 
date of this AD, whichever occurs first, accomplish paragraph (a)(1) 
or (a)(2) of this AD, as applicable.
    (1) For Model A300, A300-600, and A310 series airplanes: Replace 
the four bearings located on both throttle control levers with new 
sealed bearings, in accordance with Airbus Service Bulletin A300-76-
0018, dated October 12, 1995, as revised by Airbus Service Bulletin 
Change Notice O.A., dated February 18, 1997 (for Model A300 series 
airplanes); Airbus Service Bulletin A300-76-6010, dated October 12, 
1995, as revised by Airbus Service Bulletin Change Notice O.A, dated 
February 18, 1997 (for Model A300-600 series airplanes); or Airbus 
Service Bulletin A310-76-2013, dated October 12, 1995, as revised by 
Airbus Service Bulletin Change Notice O.A., dated February 18, 1997; 
as applicable.
    (2) For Model A310 and A300-600 series airplanes equipped with 
full authority digital engine control (FADEC): Replace the two 
throttle support assemblies equipped with rollers with new throttle 
support assemblies equipped with bearings, in accordance with Airbus 
Service Bulletin A310-76-2014, Revision 2, dated January 6, 1997 
(for Model A310 series airplanes); or Airbus Service Bulletin A300-
76-6011, Revision 2, dated January 6, 1997 (for Model A300-600 
series airplanes); as applicable.

    Note 2: Replacements accomplished prior to the effective date of 
this AD in accordance with Airbus Service Bulletin A310-76-2014, 
Revision 1, dated March 25, 1996; or Airbus Service Bulletin A300-
76-6011, Revision 1, dated March 25, 1996; are considered acceptable 
for compliance with the applicable action specified in paragraph 
(a)(2) of this AD.
    (b) 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, International Branch, ANM-116, 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, International 
Branch, ANM-116.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (c) 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.

    Note 4: The subject of this AD is addressed in French 
airworthiness directive 96-270-209 (B), dated November 20, 1996.

    Issued in Renton, Washington, on November 20, 1997.
Stewart R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-31158 Filed 11-26-97; 8:45 am]
BILLING CODE 4910-13-P