[Federal Register Volume 63, Number 86 (Tuesday, May 5, 1998)]
[Proposed Rules]
[Pages 24760-24762]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11889]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-18-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A320 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 A320 series
airplanes. This proposal would require repetitive inspections to detect
fatigue cracking of the front spar vertical stringers on the wings; and
repair, if necessary. This proposal also provides for an optional
terminating action for the repetitive inspections. 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 of
the front spar vertical stringers on the wings, which could result in
reduced structural integrity of the airframe.
DATES: Comments must be received by June 4, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-18-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-18-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-18-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 A320 series airplanes. The
DGAC advises that, during full-scale fatigue testing on a Model A320
test article, fatigue cracking occurred at 116,151 simulated flights on
the front vertical stringer on the wing at frame 36. Such fatigue
cracking, if not detected and corrected in a timely manner, could
result in reduced structural integrity of the airframe.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A320-57-1016, Revision 1, dated
December 6, 1995, which describes procedures for repetitive eddy
current
[[Page 24761]]
inspections to detect fatigue cracking of the front spar vertical
stringers on the wings.
In addition, Airbus has issued Service Bulletin A320-57-1017,
Revision 01, dated March 17, 1997, which describes procedures for
modification of the front spar vertical stringers on the wings. The
modification includes the installation of new shims and new fasteners
on the front spar vertical stringers on the wings. Accomplishment of
this modification would eliminate the need for the repetitive
inspections described in Airbus Service Bulletin A320-57-1016, Revision
1.
Accomplishment of the actions specified in these service bulletins
is intended to adequately address the identified unsafe condition. The
DGAC classified Airbus Service Bulletin A320-57-1016, Revision 1, dated
December 6, 1995, as mandatory and issued French airworthiness
directive 97-311-105(B), dated October 22, 1997, in order to assure the
continued airworthiness of these airplanes in France.
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 inspections specified in Airbus Service Bulletin A320-57-1016,
Revision 1, dated December 6, 1995, except as discussed below. This
proposed AD also would provide for 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
detect fatigue cracking before it represents a hazard to the airplane.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although Airbus Service Bulletin A320-
57-1016, Revision 1, dated December 6, 1995, 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 either the
FAA or the DGAC (or its delegated agent). In light of the type of
repair that would be required to address the identified unsafe
condition, and in consonance with existing bilateral airworthiness
agreements, the FAA has determined that, for this proposed AD, a repair
approved by either the FAA or the DGAC would be acceptable for
compliance with this proposed AD.
Differences Between Proposed Rule and Foreign AD
Operators should note that, unlike the procedures described in
French airworthiness directive 97-311-105(B), dated October 22, 1997,
this proposed AD would not permit further flight if fatigue cracks are
detected on the front spar vertical stringers of the wings. The FAA has
determined that, because of the safety implications and consequences
associated with such fatigue cracking, any subject front spar vertical
stringer that is found to be cracked must be repaired prior to further
flight in accordance with a method approved by the FAA or the DGAC (or
its delegated agent).
Cost Impact
The FAA estimates that 16 airplanes of U.S. registry would be
affected by this proposed AD. It would take approximately 2 work hours
per airplane to accomplish the proposed inspection, at an average labor
rate of $60 per work hour. Based on these figures, the cost impact of
the inspection proposed by this AD on U.S. operators is estimated to be
$1,920, 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
modification, rather than continue the repetitive inspections, it would
require approximately 6 work hours to accomplish it, at an average
labor rate of $60 per work hour. Required parts would cost
approximately $700 per airplane. Based on these figures, the cost
impact of the optional terminating modification proposed by this AD on
U.S. operators is estimated to be $1,060 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-18-AD.
Applicability: Model A320 series airplanes on which Airbus
Modification 21290 (reference Airbus Service Bulletin A320-57-
[[Page 24762]]
1017, Revision 01, dated March 17, 1997) 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
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 (c) 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 front spar
vertical stringers on the wings, which could result in reduced
structural integrity of the airframe, accomplish the following:
(a) Prior to the accumulation of 24,000 total flight cycles, or
within 60 days after the effective date of this AD, whichever occurs
later: Perform an eddy current inspection to detect fatigue cracking
of the front spar vertical stringers on the wings, in accordance
with Airbus Service Bulletin A320-57-1016, Revision 1, dated
December 6, 1995.
(1) If no crack is detected, repeat the eddy current inspection
thereafter at intervals not to exceed 14,000 flight cycles.
(2) If any crack is detected, prior to further flight, repair in
accordance with a method approved by the Manager, International
Branch, ANM-116, FAA, Transport Airplane Directorate; or the
Direction Generale de l'Aviation Civile (or its delegated agent).
Thereafter, repeat the eddy current inspection at intervals not to
exceed 14,000 flight cycles.
(b) Modification of the front spar vertical stringers on the
wings, in accordance with Airbus Service Bulletin A320-57-1017,
Revision 01, dated March 17, 1997, constitutes terminating action
for the repetitive inspection requirements 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, 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.
(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.
Note 3: The subject of this AD is addressed in French
airworthiness directive 97-311-105(B), dated October 22, 1997.
Issued in Renton, Washington, on April 29, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-11889 Filed 5-4-98; 8:45 am]
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