[Federal Register Volume 63, Number 91 (Tuesday, May 12, 1998)]
[Proposed Rules]
[Pages 26102-26104]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-12518]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-156-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A320 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

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 inner flange of door frame 66, and corrective actions, 
if necessary. This proposal also would provide 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 correct such fatigue cracking, which 
could result in reduced structural integrity of the airplane.

DATES: Comments must be received by June 11, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-156-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, 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 97-NM-156-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

[[Page 26103]]

FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket 
No. 97-NM-156-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 fatigue testing on a Model A320 test article, 
between 60,500 and 85,700 flight cycles, three cracks developed on the 
inner flange of door frame 66 at stringer 18 and stringer 20. The 
cracks were located around the edges of the gusset plate attachment 
holes of the inner flange of door frame 66, which, during routine 
visual inspection, would be hidden by the gusset plates. 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 A320-53-1071, dated November 7, 
1995, as revised by Change Notice 0A, dated July 5, 1996. This service 
bulletin describes procedures for repetitive rotating probe eddy 
current inspections to detect cracking around the edges of the gusset 
plate attachment holes of the inner flange of door frame 66, left and 
right, at stringer positions P18, P20, P22, P18', P20', and P22'. The 
DGAC classified this service bulletin as mandatory and issued French 
airworthiness directive 96-234-087(B), dated October 23, 1996, in order 
to assure the continued airworthiness of these airplanes in France. 
Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.
    Airbus also has issued Service Bulletin A320-53-1072, dated 
November 7, 1995, as revised by Change Notice 0A, dated July 5, 1996. 
This service bulletin describes procedures for modification of the 
gusset plate attachment holes. The modification involves cold working 
the attachment holes of the inner flange of door frame 66, left and 
right, at stringer positions P18, P20, P22, P18', P20', and P22.. 
Accomplishment of the modification would eliminate the need for the 
repetitive inspections. The DGAC has approved this service bulletin.

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 Service Bulletin A320-53-1071 described 
previously, except as described in the following section. 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 the Proposed AD and the Foreign Service 
Information

    The proposed AD would differ from the previously described Airbus 
service bulletins and French airworthiness directive, which specify 
that Airbus be contacted for a repair solution for cracking detected 
during an inspection. In the proposed AD, however, repair of any crack 
would be required to be accomplished in accordance with a method 
approved by the FAA.
    Also, operators should note that, unlike the procedures described 
in Airbus Service Bulletin A320-53-1071, this proposed AD would not 
permit further flight if cracks are detected around the edges of the 
gusset plate attachment holes of the inner flange of door frame 66. The 
FAA has determined that, because of the safety implications and 
consequences associated with such cracking, any subject attachment hole 
that is found to have cracking must be repaired or modified prior to 
further flight.

Cost Impact

    The FAA estimates that 132 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 8 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 $63,360, or $480 per 
airplane.
    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 proposed modification, 
it would take approximately 5 work hours per airplane to accomplish the 
actions, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of the modification proposed by this AD on 
U.S. operators is estimated to be $300 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

[[Page 26104]]

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 97-NM-156-AD.

    Applicability: Model A320 series airplanes on which Airbus 
Modification 21778 (reference Airbus Service Bulletin A320-53-1072, 
dated November 7, 1995, as revised by Change Notice 0A, dated July 
5, 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 (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 correct fatigue cracking in the inner flange of door frame 
66, left and right, which could result in reduced structural 
integrity of the airplane, accomplish the following:
    (a) Prior to the accumulation of 20,000 total flight cycles, or 
within 1 year after the effective date of this AD, whichever occurs 
later: Perform a rotating probe eddy current inspection to detect 
cracking around the edges of the gusset plate attachment holes of 
the inner flange of door frame 66, left and right, at stringer 
positions P18, P20, P22, P18', P20', and P22', in accordance with 
Airbus Service Bulletin A320-53-1071, dated November 7, 1995, as 
revised by Change Notice 0A, dated July 5, 1996. 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. Repeat the inspection thereafter at 
intervals not to exceed 20,000 flight cycles.
    (b) Modification of the gusset plate attachment holes of the 
inner flange of door frame 66, left and right (Airbus Modification 
21778), in accordance with Airbus Service Bulletin A320-53-1072, 
dated November 7, 1995, as revised by Change Notice 0A, dated July 
5, 1996, 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 96-234-087(B), dated October 23, 1996.

    Issued in Renton, Washington, on May 5, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-12518 Filed 5-11-98; 8:45 am]
BILLING CODE 4910-13-U