[Federal Register Volume 63, Number 80 (Monday, April 27, 1998)]
[Proposed Rules]
[Pages 20546-20548]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11090]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-77-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 
cracking in the pressurized floor pick-up angles on the rear spar of 
the wing, and replacement of any cracked pick-up angle and its 
associated diaphragms with improved parts. Such replacement would 
terminate the repetitive inspections for that angle. 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 in the 
pressurized floor pick-up angles at the rear spar of the wing, which 
could result in reduced structural integrity of the airframe.

DATES: Comments must be received by May 27, 1998.


[[Page 20547]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-77-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-77-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-77-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 or develop on certain Airbus Model A320 series 
airplanes. The DGAC advises that, during fatigue testing, cracking was 
found on a test article in the pressurized floor pick-up angles at the 
rear spar of the wing. 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

    The manufacturer has issued Airbus Service Bulletin A320-57-1090, 
Revision 01, dated June 10, 1997, which describes procedures for 
repetitive eddy current inspections to detect cracking in the 
pressurized floor pick-up angles on the rear spar of the wing. The 
manufacturer also has issued Airbus Service Bulletin A320-57-1025, 
Revision 05, dated June 26, 1997, which describes procedures for 
replacing any cracked pick-up angle and its associated diaphragms with 
improved parts. Accomplishment of the replacement involves removing 
existing fasteners, diaphragms, and pick-up angles; installing improved 
pick-up angles, diaphragms, and fasteners; cold expanding certain 
fastener holes; and performing a rotating probe inspection for cracking 
of the fastener holes. Such replacement would eliminate the need for 
the repetitive inspection requirement for that pick-up angle. 
Accomplishment of the replacement is intended to adequately address the 
identified unsafe condition.
    The DGAC classified Airbus Service Bulletin A320-57-1090 as 
mandatory and issued French airworthiness directive CN 97-084-097 (B), 
dated March 12, 1997, in order to assure the 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 
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 inspections specified in Airbus Service Bulletin A320-57-1090, 
Revision 01, 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 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 A320-57-1090, this proposed AD would not permit 
further flight if cracks are detected in any pressurized floor pick-up 
angle. The FAA has determined that, because of the safety implications 
and consequences associated with such cracking, any subject pressurized 
floor pick-up angle that is found to be cracked must be replaced prior 
to further flight.
    Operators also should note that, although Airbus Service Bulletin 
A320-57-1025 specifies that the manufacturer may be contacted for 
disposition of certain repair conditions associated with accomplishment 
of the replacement, 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.

[[Page 20548]]

Cost Impact

    The FAA estimates that 120 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 8 work 
hours per airplane (including access and close) 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 $57,600, or $480 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 
action that would be provided by this proposed AD action, it would take 
approximately 140 work hours to accomplish, at an average labor rate of 
$60 per work hour. The cost of required parts would be approximately 
$10,103 per airplane. Based on these figures, the cost impact of that 
optional terminating action would be $18,503 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-77-AD.

    Applicability: Model A320 series airplanes, as listed in Airbus 
Service Bulletin A320-57-1090, Revision 01, dated June 10, 1997; 
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 request approval for an 
alternative method of compliance in accordance with paragraph (d) 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 in the pressurized floor pick-up 
angles at the rear spar of the wing, which could result in reduced 
structural integrity of the airframe, accomplish the following:
    (a) Prior to the accumulation of 20,000 total flight cycles, or 
within 60 days after the effective date of this AD, whichever occurs 
later: Perform an eddy current inspection to detect cracking in the 
pressurized floor pick-up angles on the rear spar of the wing, in 
accordance with Airbus Service Bulletin A320-57-1090, Revision 01, 
dated June 10, 1997.
    (1) If no cracking is found, repeat the inspection thereafter at 
intervals not to exceed 10,000 flight cycles.
    (2) If any cracking is found during any inspection required by 
this AD, prior to further flight, replace each cracked pick-up angle 
and its associated diaphragms with improved parts, in accordance 
with Airbus Service Bulletin A320-57-1025, Revision 05, dated June 
26, 1997. For all pick-up angles not replaced with improved angles, 
repeat the inspection thereafter at intervals not to exceed 10,000 
flight cycles.
    (b) Replacement of a pick-up angle and its associated diaphragms 
with improved parts, in accordance with Airbus Service Bulletin 
A320-57-1025, Revision 05, dated June 26, 1997, constitutes 
terminating action for the repetitive inspection requirements for 
that pick-up angle.
    (c) If any crack is detected during any inspection required by 
this AD, and the applicable service bulletin specifies to contact 
Airbus for appropriate action: Prior to further flight, repair in 
accordance with a method approved by either the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate; 
or the Direction Generale de l'Aviation Civile (or its delegated 
agent).
    (d) 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 request 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.

    (e) Special flight permits may be issued in accordance with 
Secs. 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 CN 97-084-097 (B), dated March 12, 1997.

    Issued in Renton, Washington, on April 21, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-11090 Filed 4-24-98; 8:45 am]
BILLING CODE 4910-13-U