[Federal Register Volume 63, Number 96 (Tuesday, May 19, 1998)]
[Proposed Rules]
[Pages 27516-27519]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-13311]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-78-AD]
RIN 2120-AA64


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 inspections to 
detect cracking of the doubler angle and discrepancies of the fasteners 
that connect the doubler angle and the bottom panel of the center wing 
box, and corrective actions, 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 fatigue cracking in the doubler 
angle and discrepancies of the fasteners that connect the doubler angle 
and the bottom panel of the center wing box. Such cracking and 
discrepancies could result in reduced structural integrity of the 
airplane.

DATES: Comments must be received by June 18, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-78-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:

[[Page 27517]]

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-78-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-114, Attention: Rules 
Docket No. 98-NM-78-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 A300-600 series airplanes. 
The DGAC advises that, during full-scale fatigue testing of the Airbus 
Model A300 series airplane, cracking was found on the forward doubler 
angle at the junction with the lower surface of the wing. This cracking 
originated in the seventh fastener hole, starting from the front, on 
the face of the doubler angle that is attached to the lower surface of 
the wing. The DGAC has received reports of cracking in the same 
location on in-service airplanes, which has been attributed to fatigue 
caused by the relative movement between the fuselage skin panel and the 
lower wing skin. Such fatigue cracking, if not corrected, could result 
in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A300-53-6110, dated April 8, 
1997, which describes procedures for performing repetitive detailed 
visual inspections to detect cracking of the doubler angle, and 
repetitive detailed external visual inspections to detect discrepancies 
(i.e., damage, stretching, cracking, or distortion) of the fasteners 
that connect the doubler angle and the bottom panel of the center wing 
box. This service bulletin also describes procedures for replacing 
discrepant fasteners with new fasteners, and performing follow-on 
corrective actions. (These follow-on actions include performing a 
rotating probe inspection of the fastener hole to detect cracking or 
distortion and repairing the fastener hole, if cracking is detected.)
    The DGAC classified Airbus Service Bulletin A300-53-6110 as 
mandatory and issued French airworthiness directive 97-383-240(B), 
dated December 17, 1997, in order to assure the continued airworthiness 
of these airplanes in France.
    Airbus also has issued Service Bulletin A300-53-6063, dated 
December 12, 1996, which describes procedures for replacing the 
existing doubler angle with a longer splice plate and an improved 
doubler angle. Accomplishment of this replacement would eliminate the 
need for the repetitive inspections described previously.

FAA's Conclusions

    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 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 bulletin described previously, 
except as discussed below. This proposed AD also would provide for an 
optional terminating action for the repetitive inspections.
    Operators should note that, in consonance with the findings of the 
DGAC, the FAA has determined that the repetitive inspections proposed 
by this AD can be allowed to continue in lieu of accomplishment of a 
terminating action. In making this determination, the FAA considers 
that, in this case, long-term continued operational safety will be 
adequately assured by accomplishing the repetitive inspections to 
correct cracking before it represents a hazard to the airplane.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that, unlike the procedures described in 
Airbus Service Bulletin A300-53-6110, this proposed AD would not permit 
further flight if any crack is found in the doubler angle, or if any 
discrepancy is found in the fastener holes or the fasteners that 
connect the doubler angle and the bottom panel of the center wing box. 
The FAA has determined that, because of the safety implications and 
consequences associated with such cracking or discrepancies, any 
subject doubler angle that is found to be cracked or any fastener that 
is found to be discrepant must be replaced prior to further flight.
    Operators also should note that, although Airbus Service Bulletin 
A300-53-6110 specifies that the manufacturer may be contacted for 
disposition of certain repair conditions, this proposal would require 
the repair of those conditions to be accomplished in accordance with a 
method approved by the FAA.

Cost Impact

    The FAA estimates that 54 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 2 work 
hours per airplane to accomplish the proposed inspections, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the inspections proposed by this AD on U.S. operators is 
estimated to be $6,480, or $120 per airplane, per inspection cycle.
    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.
    Should an operator elect to accomplish the optional terminating

[[Page 27518]]

action specified in Airbus Service Bulletin A300-53-6063 that would be 
provided by this AD action, it would take approximately 109 work hours 
to accomplish it, at an average labor rate of $60 per work hour. The 
cost of required parts would be approximately $4,028 per airplane. 
Based on these figures, the cost impact of that optional terminating 
action would be $10,568 per airplane.

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-78-AD.

    Applicability: Model A300-600 series airplanes, on which Airbus 
Modification 11044 or Airbus Modification 11045 (reference Airbus 
Service Bulletin A300-53-6063, dated December 12, 1996) has not been 
accomplished, 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 (f) 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 fatigue cracking of the doubler angle and 
discrepancies of the fasteners that connect the doubler angle and 
the bottom panel of the center wing box, which could result in 
reduced structural integrity of the airplane, accomplish the 
following:
    (a) Perform a detailed visual inspection to detect cracking of 
the doubler angle, and a detailed external visual inspection to 
detect discrepancies of the fasteners that connect the doubler angle 
and the bottom panel of the center wing box, on the left and right 
sides of the airplane, in accordance with Airbus Service Bulletin 
A300-53-6110, dated April 8, 1997, at the time specified in 
paragraph (a)(1) or (a)(2) of this AD, as applicable. Thereafter, 
repeat the inspections of the doubler angle and fasteners at 
intervals not to exceed 2,400 flight cycles.
    (1) For airplanes on which a detailed visual inspection has been 
performed within the last 2,400 flight cycles prior to the effective 
date of this AD, in accordance with Structural Significant Item 
(SSI) 57-10-19 of the Airbus A300-600 Maintenance Review Board (MRB) 
Document: Inspect within 2,400 flight cycles after the most recent 
SSI inspection.
    (2) For airplanes on which a detailed visual inspection has not 
been performed within the last 2,400 flight cycles prior to the 
effective date of this AD, in accordance with Structural Significant 
Item (SSI) 57-10-19 of the Airbus A300-600 Maintenance Review Board 
(MRB) Document: Inspect at the time specified in paragraph 
(a)(2)(i), (a)(2)(ii), or (a)(2)(iii), as applicable.
    (i) For airplanes that have accumulated 6,600 or more total 
flight cycles as of the effective date of this AD: Inspect within 
750 flight cycles after the effective date of this AD.
    (ii) For airplanes that have accumulated more than 3,100 total 
flight cycles, but less than 6,600 total flight cycles as of the 
effective date of this AD: Inspect within 1,500 flight cycles after 
the effective date of this AD.
    (iii) For airplanes that have accumulated 3,100 total flight 
cycles or less as of the effective date of this AD: Inspect prior to 
the accumulation of 4,600 total flight cycles.
    (b) If any discrepancy is found in a fastener that connects the 
doubler angle and the bottom panel of the center wing box during any 
detailed external visual inspection performed in accordance with 
paragraph (a) of this AD: Prior to further flight, remove the 
discrepant fastener, and perform a rotating probe inspection to 
detect discrepancies of the fastener holes, in accordance with 
Airbus Service Bulletin A300-53-6110, dated April 8, 1997.
    (1) If no discrepancy is found in any fastener hole, prior to 
further flight, install a new fastener, in accordance with the 
service bulletin. Thereafter, repeat the inspections required by 
paragraph (a) of this AD at intervals not to exceed 2,400 flight 
cycles.
    (2) If any discrepancy is found in any fastener hole, prior to 
further flight, except as provided by paragraph (e) of this AD, 
repair in accordance with the service bulletin, and accomplish the 
actions required by paragraph (c) of this AD.
    (c) If any crack is found in the doubler angle during any 
detailed visual inspection performed in accordance with paragraph 
(a) of this AD, prior to further flight, modify the doubler angle in 
accordance with Airbus Service Bulletin A300-53-6063, dated December 
12, 1996. Accomplishment of the modification constitutes terminating 
action for both repetitive inspection requirements of this AD.
    (d) Accomplishment of the modification in accordance with Airbus 
Service Bulletin A300-53-6063, dated December 12, 1996, constitutes 
terminating action for the repetitive inspection requirements of 
this AD.
    (e) If any discrepancy of a fastener hole is found during any 
inspection of a discrepant fastener as required by paragraph (b) of 
this AD, and the service bulletin specifies to contact Airbus for 
appropriate action: Prior to further flight, repair in accordance 
with a method approved by the Manager, International Branch, ANM-
116, FAA, Transport Airplane Directorate.
    (f) 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. 
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.

    (g) 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 97-383-240(B), dated December 17, 1997.


[[Page 27519]]


    Issued in Renton, Washington, on May 13, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-13311 Filed 5-18-98; 8:45 am]
BILLING CODE 4910-13-P