[Federal Register Volume 63, Number 76 (Tuesday, April 21, 1998)]
[Proposed Rules]
[Pages 19684-19686]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10488]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-81-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300 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 adoption of a new airworthiness 
directive (AD) that is applicable to certain Airbus Model A300 and all 
Model A300-600 series airplanes. This proposal would require a one-time 
inspection for cracking of the gantry lower flanges in the main landing 
gear (MLG) bay area; and repair, if necessary. This proposal is 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. The actions specified by 
the proposed AD are intended to detect and correct cracking of the 
gantry lower flanges in the MLG bay area, which could result in 
decompression of the airplane.

DATES: Comments must be received by May 21, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-81-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: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; 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 98-NM-81-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

[[Page 19685]]

FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket 
No. 98-NM-81-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, notified the FAA that an unsafe 
condition may exist on certain Airbus Model A300 and all Model A300-600 
series airplanes. The DGAC advises that, during an inspection on a 
Model A300-600 series airplane, cracks were found at 20,600 flight 
cycles between left-hand frames 51 and 52 on the gantry (frame support 
structure) lower flange 4 in the main landing gear (MLG) bay area. In 
addition, the DGAC advises that, during an inspection on a Model A300-
600 series airplane, cracks were found at 16,800 flight cycles between 
right-hand frames 50B, 51A, and 52A and at left-hand frame 50B on the 
gantry lower flange 5. Such cracking, if not corrected, could result in 
decompression of the airplane.
    The cause of the cracking in this area is still under 
investigation. However, the gantry lower flanges on certain Model A300 
series airplanes are identical in design to those on Model A300-600 
series airplanes; therefore, both models may be subject to the same 
unsafe condition.

Explanation of Relevant Service Information

    Airbus has issued All Operators Telex (AOT) 53-11, dated October 
13, 1997, which describes procedures for a one-time ultrasonic 
inspection for cracking of the gantry lower flanges in the MLG bay 
area. This AOT also describes procedures for repair of cracks. The 
repair involves stop drilling of cracks as a temporary repair, or 
installing a doubler on the gantry lower flange to reinforce the area. 
The DGAC classified this AOT as mandatory and issued French 
airworthiness directive 97-372-236(B), dated December 3, 1997, 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 
Sec. 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 AOT described previously, except as 
discussed below.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Differences Between Proposed Rule and Service Information

    Operators should note that, unlike the procedures described in 
Airbus AOT 53-11, dated October 13, 1997, this proposed AD would not 
permit further flight if cracks are detected in the gantry lower 
flanges in the MLG bay area. The FAA has determined that, because of 
the safety implications and consequences associated with such cracking, 
any subject gantry lower flange that is found to be cracked must be 
repaired or modified prior to further flight.

Cost Impact

    The FAA estimates that 67 airplanes of U.S. registry would be 
affected by this proposed AD. It would take approximately 4 work hours 
per airplane to accomplish the proposed inspection, at an average labor 
rate of $60 per work hour. Based on this figure, the cost impact of the 
proposed AD on U.S. operators is estimated to be $16,080, or $240 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 98-NM-81-AD.

    Applicability: Model A300 series airplanes on which Airbus 
Modification 3474 has been accomplished, and all Model 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 
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 detect and correct cracking of the gantry lower flanges in 
the main landing gear (MLG) bay area, which could result in

[[Page 19686]]

decompression of the airplane, accomplish the following:
    (a) Prior to the accumulation of 16,300 total flight cycles, or 
within 500 flight cycles after the effective date of this AD, 
whichever occurs later, perform a one-time ultrasonic inspection for 
cracking of the gantry lower flanges in the MLG bay area, in 
accordance with Airbus All Operators Telex (AOT) 53-11, dated 
October 13, 1997.
    (1) If any cracking is detected, prior to further flight, repair 
in accordance with the AOT.
    (2) If no cracking is detected, no further action is required by 
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 2: 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 3: The subject of this AD is addressed in French 
airworthiness directive 97-372-236(B), dated December 3, 1997.

    Issued in Renton, Washington, on April 15, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-10488 Filed 4-20-98; 8:45 am]
BILLING CODE 4910-13-U