[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
