[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)]
[Proposed Rules]
[Pages 15441-15443]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8253]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-215-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Airbus Model A300, A300-600, 
and A310 series airplanes. This proposal would require inspecting the 
bearings located in the mechanical control linkage of the nose landing 
gear (NLG) free-fall mechanism for discrepancies, replacing any 
discrepant bearings with stainless steel bearings, and conducting a 
test to ensure that the NLG free-fall mechanism extends properly. This 
proposal is prompted by a report indicating that, during an operational 
test of the NLG, the landing gear failed to extend. The actions 
specified by the proposed AD are intended to prevent the bearings from 
seizing, which could lead to the loss of NLG free-fall extension 
capability.

DATES: Comments must be received by May 12, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-215-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: Charles Huber, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2589; 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 96-NM-215-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. 96-NM-215-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    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 A300, A300-600, and A310 
series airplanes. The DGAC advises that one Model A300 operator 
reported that, during an operational test of free-fall extension of the 
nose landing gear (NLG), the free-fall handle could not be rotated and 
the NLG failed to extend.
    Investigations revealed that after 17,000 flight cycles and 27,000 
flight hours, four bearings of the NLG free-fall mechanism were 
severely corroded and had seized. The bearings are located in the 
mechanical control linkage of the NLG free-fall mechanism. Analysis 
disclosed that the corroded bearings were made of carbon steel instead 
of stainless steel, as specified in the type design.
    Corrosion of the bearings could cause them to seize, which, if not 
corrected,

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could lead to the loss of NLG free-fall extension capability.

Explanation of Relevant Service Information

    Airbus has issued the following service bulletins, all dated April 
29, 1996, which describe procedures for inspecting the four bearings 
located in the mechanical control linkage of the NLG free-fall 
mechanism for discrepancies, replacing carbon steel bearings with 
stainless steel bearings, and conducting a test to ensure that the NLG 
free-fall mechanism extends properly:
    <bullet> Service Bulletin A300-32-0418, Revision 1.
    <bullet> Service Bulletin A300-32-6061, Revision 1.
    <bullet> Service Bulletin A310-32-2098, Revision 1.
    Accomplishment of these procedures will preclude potential 
corrosion and seizure of the bearings, which could lead to the loss of 
NLG free-fall extension capability.
    The DGAC classified these service bulletins as mandatory and issued 
French airworthiness directive (C/N) 96-052-197(B), dated March 13, 
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 inspecting the four 
bearings located in the mechanical control linkage of the NLG free-fall 
mechanism for discrepancies, replacing discrepant bearings with 
stainless steel bearings, and conducting a test to ensure that the NLG 
free-fall mechanism extends properly. The actions would be required to 
be accomplished in accordance with the service bulletins described 
previously.

Cost Impact

    The FAA estimates that 127 Model A300, A300-600, and A310 series 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 14 work hours per airplane to accomplish 
the proposed actions, and that the average labor rate is $60 per work 
hour. Required parts would cost approximately $552 per airplane. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $176,784, or $1,392 per airplane.
    The cost impact figure discussed above is 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 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 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 96-NM-215-AD.

    Applicability: All Model A300, A300-600, and A310 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 
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 (d) 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 the bearings in the mechanical control linkage of the 
nose landing gear (NLG) free-fall mechanism from seizing, which 
could lead to the loss of NLG free-fall extension capability, 
accomplish the following:
    (a) Within 30 days after the effective date of this AD, conduct 
an inspection to determine whether carbon steel or stainless steel 
bearings are installed in the mechanical control linkage of the NLG 
free-fall mechanism, in accordance with Airbus Service Bulletin 
A300-32-0418 (for Model A300 series airplanes), A300-32-6061 (for 
Model A300-600 series airplanes), or A310-32-2098 (for Model A310 
series airplanes), all Revision 1, all dated April 29, 1996.
    (b) If stainless steel bearings are installed, prior to further 
flight, conduct a test to ensure that the NLG free-fall mechanism 
extends properly, in accordance with Airbus Service Bulletin A300-
32-0418 (for Model A300 series airplanes), A300-32-6061 (for Model 
A300-600 series airplanes), or A310-32-2098 (for Model A310 series 
airplanes), all Revision 1, all dated April 29, 1996.
    (c) If carbon steel bearings are installed, prior to further 
flight, replace them with stainless steel bearings, and conduct a 
test to ensure that the NLG free-fall mechanism extends properly, in 
accordance with Airbus Service Bulletin A300-32-0418 (for Model A300 
series airplanes), A300-32-6061 (for Model A300-600 series 
airplanes), or A310-32-2098 (for Model A310 series airplanes), all 
Revision 1, all dated April 29, 1996.
    (d) An alternative method of compliance or adjustment of the 
compliance time that

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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 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.

    Issued in Renton, Washington, on March 26, 1997.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-8253 Filed 3-31-97; 8:45 am]
BILLING CODE 4910-13-U