[Federal Register Volume 59, Number 240 (Thursday, December 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30802]


[[Page Unknown]]

[Federal Register: December 15, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-192-AD]

 

Airworthiness Directives; Airbus Model 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 A300-600 
series airplanes. This proposal would require repetitive ultrasonic 
inspections to detect cracks in the bolt holes inboard and outboard of 
rib 9 on the bottom booms of the front and rear wing spars, and repair, 
if necessary. This proposal is prompted by the discovery of fatigue 
cracks that emanated from the bolt holes inboard and outboard of rib 9 
in the bottom booms of the front and rear wing spars. The actions 
specified by the proposed AD are intended to prevent reduced structural 
integrity of a wing spar as a result of fatigue cracks in the bolt 
holes.

DATES: Comments must be received by January 26, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-192-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, 
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:

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 94-NM-192-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. 94-NM-192-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 certain Airbus Model A300-600 series 
airplanes. The DGAC advises that, during full-scale fatigue testing of 
Model A300 series airplanes, fatigue cracks were found that emanated 
from the bolt holes inboard and outboard of rib 9 in the bottom booms 
of the front and rear wing spars. The cracks were discovered at 58,650 
simulated flight cycles. Additionally, the DGAC received six reports of 
cracks found in the bottom booms of the front and rear wing spars at 
the rib 9 joint on an in-service Model A300-B2 series airplane. The 
cracks were discovered between 19,500 and 29,700 flight cycles. Model 
A300-600 series airplanes are similar in type design to Model A300 
series airplanes and, therefore, are subject to the cracking that was 
discovered on Model A300 series airplanes.
    Fatigue cracks in the lower boom of the front and rear wing spars, 
if not detected and corrected in a timely manner, could result in 
reduced structural integrity of a wing spar.
    Airbus has issued Service Bulletin A300-57-6037, dated August 1, 
1994, which describes procedures for repetitive ultrasonic inspections 
to detect cracks in the bolt holes inboard and outboard of rib 9 on the 
bottom booms of the front and rear wing spars, and repair, if 
necessary. The DGAC classified this service bulletin as mandatory and 
issued French airworthiness directive 94-208-169(B), dated September 
14, 1994, in order to assure the continued airworthiness of these 
airplanes in France.
    This airplane model is manufactured in France and is type 
certificated or 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.
    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 repetitive 
ultrasonic inspections to detect cracks in the bolt holes inboard and 
outboard of rib 9 on the bottom booms of the front and rear wing spars, 
and repair, if necessary. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.
    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. Under 
these circumstances, at least one operator appears to have incorrectly 
assumed that its airplane was not subject to an AD. On the contrary, 
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 requirement.
    The FAA estimates that 35 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 11 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
total cost impact of the proposed AD on U.S. operators is estimated to 
be $23,100, or $660 per airplane, per inspection cycle.
    The total 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.
    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. 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:

Airbus Industrie: Docket 94-NM-192-AD.

    Applicability: Model A300-600 series airplanes on which Airbus 
Modification 10161 has not been installed; 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 (c) 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 reduced structural integrity of a wing spar, 
accomplish the following:
    (a) Perform an ultrasonic inspection to detect cracks in the 
bolt holes inboard and outboard of rib 9 on the bottom booms of the 
front and rear wing spars, in accordance with Airbus Service 
Bulletin A300-57-6037, dated August 1, 1994, at the time specified 
in paragraph (a)(1) or (a)(2) of this AD, as applicable.
    (1) For airplanes on which Airbus Modification 8842 (reference 
Airbus Service Bulletin A300-57-6039) has not been installed: Prior 
to the accumulation of 17,000 total landings, or within 2,000 
landings after the effective date of this AD, whichever occurs 
later. Repeat the inspection thereafter at intervals not to exceed 
9,000 landings.
    (2) For airplanes on which Airbus Modification 8842 has been 
installed: Prior to the accumulation of 17,000 total landings after 
accomplishment of Airbus Modification 8842, or within 2,000 landings 
after the effective date of this AD, whichever occurs later. Repeat 
the inspection thereafter at intervals not to exceed 9,000 landings.
    (b) If any crack is found, prior to further flight, repair in 
accordance with Airbus Service Bulletin A300-57-6037, dated August 
1, 1994. Thereafter, perform the repetitive inspections required by 
paragraph (a) of this AD.
    (c) 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 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.

    (d) 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 December 9, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-30802 Filed 12-14-94; 8:45 am]
BILLING CODE 4910-13-U