[Federal Register Volume 63, Number 71 (Tuesday, April 14, 1998)]
[Proposed Rules]
[Pages 18164-18167]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9753]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-08-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 all Airbus Model A320 series 
airplanes. This proposal would require repetitive inspections to detect 
fatigue cracking in certain areas of the fuselage; and corrective 
action, 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 detect and correct fatigue cracking of 
the fuselage, which could result in reduced structural integrity of the 
airplane.

DATES: Comments must be received by May 14, 1998.


[[Page 18165]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-08-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-08-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-08-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 all Airbus Model A320 series airplanes. The DGAC 
advises that, during full-scale fatigue testing, cracking was detected 
at flight cycles varying from 76,000 to 111,664 in several areas of the 
fuselage:
     On the bottom panel of the keel beam at the frame 46, 
stringer 37 intersection at the pressure bulkhead;
     On the outboard flanges of frames 38 through 41, between 
stringers 12 and 21, originating at the fastener holes; and
     On the upper rivet row on the outer skin panel of the 
longitudinal lap joint, between frames 53 and 54, in the area of 
stringer 6; and between frames 48 and 64.
    Such fatigue cracking, if not detected and corrected in a timely 
manner, could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A320-53-1034, dated March 30, 
1992, which describes procedures for repetitive ultrasonic inspections 
to detect cracking in the bottom panels of the keel beam (both left and 
right), in the area of the frame 46 and stringer 37 intersection at the 
pressure bulkhead; and repair, if necessary.
    Airbus also has issued Service Bulletin A320-53-1033, Revision 3, 
dated July 4, 1994, which describes procedures for modification of six 
specific fastener holes in the area of the frame 46 and stringer 37 
intersection. This modification involves removing existing fasteners; 
cleaning the fastener holes; performing an eddy current inspection of 
the fastener holes to detect cracking, and repairing cracking if 
necessary; cold expanding the crack-free fastener holes; and installing 
oversize fasteners. Accomplishment of this modification would eliminate 
the need for the repetitive inspections specified in Airbus Service 
Bulletin A320-53-1034.
    Airbus also has issued Service Bulletin A320-53-1032, Revision 1, 
dated January 15, 1998, which describes procedures for repetitive 
visual inspections to detect cracking on the outboard flanges around 
the fastener holes of frames 38 to 41, between stringers 12 and 21; and 
repair, if necessary.
    Airbus also has issued Service Bulletin A320-53-1031, dated 
December 9, 1994, which describes procedures for modification of frames 
38 to 41, between stringers 12 and 21. This modification involves cold 
expanding fastener holes and replacing the existing fasteners with new 
fasteners. Accomplishment of this modification, if performed prior to 
the accumulation of 20,000 total flight cycles, would eliminate the 
need for the repetitive inspections specified in Airbus Service 
Bulletin A320-53-1032.
    Airbus also has issued Service Bulletin A320-53-1057, Revision 2, 
dated July 5, 1996, which describes procedures for repetitive visual or 
eddy current inspections to detect cracking in the upper rivet row of 
the outer skin panel of the longitudinal lap joints in four specific 
areas; and repair, if necessary. The following areas are to be 
inspected:
     Between frames 48 and 64, next to stringer 6, on the left- 
and right-hand sides of the fuselage;
     Between frames 60 and 64, next to stringer 32, on the 
left-hand side of the fuselage;
     Between frames 59 and 64, next to stringer 32, on the 
right-hand side of the fuselage; and
     Between frames 58 and 64, next to stringer 41, on the 
right-hand side of the fuselage.
    Airbus also has issued Service Bulletin A320-53-1056, Revision 02, 
dated February 16, 1998, which describes procedures for modification of 
the outer skin panel of the longitudinal lap joints in multiple areas 
of the rear fuselage. This modification involves measuring the 
protrusion of existing rivets in the upper rivet rows of the 
longitudinal lap joints; and replacing existing rivets with repair 
rivets, if necessary. Accomplishment of this modification, if performed 
prior to the accumulation of 20,000 total flight cycles, would 
eliminate the need for the repetitive inspections specified in Airbus 
Service Bulletin A320-53-1057.
    Accomplishment of the modifications specified in Airbus Service 
Bulletins A320-53-1033, A320-53-1031, and A320-53-1056 is intended to 
adequately address the identified unsafe condition.
    The DGAC classified Airbus Service Bulletins A320-53-1034, A320-53-
1032, and A320-53-1057 as mandatory and issued French airworthiness 
directives 97-314-108(B), 97-313-107(B), and 97-312-106(B), all dated 
October 22, 1997, in order to assure the

[[Page 18166]]

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 actions specified in Airbus Service Bulletins A320-53-1034, A320-
53-1032, and A320-53-1057, described previously, except as discussed in 
the paragraphs that explain differences between this proposed rule and 
the service bulletins (below). In addition, this proposed AD 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 Bulletins

    Operators should note that, unlike the procedures described in 
Airbus Service Bulletins A320-53-1034, A320-53-1032, and A320-53-1057, 
this proposed AD would not permit further flight if cracking is 
detected in any section of the fuselage. The FAA has determined that, 
because of the safety implications and consequences associated with 
such cracking, any portion of the fuselage that is found to be cracked 
must be repaired or modified prior to further flight, in accordance 
with the applicable service bulletin, except as discussed in the next 
paragraph.
    Operators also should note that, although Airbus Service Bulletins 
A320-53-1034, A320-53-1033, and A320-53-1032 specify that the 
manufacturer may be contacted for disposition of certain repair 
conditions, this proposed AD 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 118 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 6 work hours per airplane to accomplish 
the proposed ultrasonic inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the ultrasonic 
inspection proposed by this AD on U.S. operators is estimated to be 
$42,480, or $360 per airplane, per inspection cycle.
    It would take approximately 19 work hours per airplane to 
accomplish the proposed visual inspection on the outboard flanges, at 
an average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the visual inspection proposed by this AD on U.S. 
operators is estimated to be $134,520, or $1,140 per airplane, per 
inspection cycle.
    It would take approximately 15 work hours per airplane to 
accomplish either the visual or eddy current inspection of the 
longitudinal lap joints, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of these inspections proposed 
by this AD on U.S. operators is estimated to be $106,200, or $900 per 
airplane, per inspection cycle.
    The cost impact figures discussed above are 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 specified in Airbus Service Bulletin A320-53-1033 that would be 
provided by this AD action, it would take approximately 5 work hours to 
accomplish it, at an average labor rate of $60 per work hour. The cost 
of required parts would be approximately $72 per airplane. Based on 
these figures, the cost impact of that optional terminating action 
would be $372 per airplane.
    Should an operator elect to accomplish the optional terminating 
action specified in Airbus Service Bulletin A320-53-1031 that would be 
provided by this AD action, it would take approximately 1 work hour 
(excluding access and closeup) per fastener hole to accomplish it, at 
an average labor rate of $60 per work hour. The cost of required parts 
would be approximately $4,047 (for one modification kit). Based on 
these figures, the cost impact of that optional terminating action 
would be a minimum of $4,107 per airplane.
    Should an operator elect to accomplish the optional terminating 
action specified in Airbus Service Bulletin A320-53-1056 that would be 
provided by this AD action, it would take approximately 258 work hours 
to accomplish it, at an average labor rate of $60 per work hour. The 
cost of required parts would be approximately $420 per airplane. Based 
on these figures, the cost impact of that optional terminating action 
would be $15,900 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:

[[Page 18167]]

    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-08-AD.

    Applicability: All Model A320 series airplanes, 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 (h) 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 fuselage, which 
could result in reduced structural integrity of the airplane, 
accomplish the following:
    (a) For airplanes on which Airbus Modification 21202 (reference 
Airbus Service Bulletin A320-53-1033, Revision 3, dated July 4, 
1994) has not been accomplished: Prior to the accumulation of 30,000 
total flight cycles, or within 6 months after the effective date of 
this AD, whichever occurs later, perform an ultrasonic inspection to 
detect cracking in the bottom panels of the keel beam (both left and 
right), in the area of the frame 46 and stringer 37 intersection at 
the pressure bulkhead, in accordance with Airbus Service Bulletin 
A320-53-1034, dated March 30, 1992. Thereafter, repeat the 
ultrasonic inspection at intervals not to exceed 6,000 flight 
cycles. If any crack is found, prior to further flight, repair in 
accordance with the service bulletin, except as provided by 
paragraph (g) of this AD.
    (b) Accomplishment of Airbus Modification 21202 in accordance 
with Airbus Service Bulletin A320-53-1033, Revision 3, dated July 4, 
1994, constitutes terminating action for the repetitive inspection 
requirement of paragraph (a) of this AD.
    (c) For airplanes on which Airbus Modification 21346 (reference 
Airbus Service Bulletin A320-53-1031, dated December 9, 1994) has 
not been accomplished prior to the accumulation of 20,000 total 
flight cycles: Prior to the accumulation of 30,000 total flight 
cycles, or within 6 months after the effective date of this AD, 
whichever occurs later, perform a visual inspection to detect 
cracking on the outboard flanges around the fastener holes of frames 
38 to 41, between stringers 12 and 21, in accordance with Airbus 
Service Bulletin A320-53-1032, Revision 1, dated January 15, 1998. 
Thereafter, repeat the visual inspection at intervals not to exceed 
6,000 flight cycles. If any crack is found, prior to further flight, 
repair in accordance with the service bulletin, except as provided 
by paragraph (g) of this AD. Accomplishment of a repair in 
accordance with the service bulletin terminates the repetitive 
inspection requirements for the area repaired.
    (d) Accomplishment of Airbus Modification 21346 in accordance 
with Airbus Service Bulletin A320-53-1031, dated December 9, 1994, 
prior to the accumulation of 20,000 total flight cycles constitutes 
terminating action for the repetitive inspection requirement of 
paragraph (c) of this AD.
    (e) For airplanes on which Airbus Modification 21905 (reference 
Airbus Service Bulletin A320-53-1056, Revision 02, dated February 
16, 1998) has not been accomplished: Prior to the accumulation of 
20,000 total flight cycles, or within 6 months after the effective 
date of this AD, whichever occurs later, perform a visual or eddy 
current inspection to detect cracking in the upper rivet row of the 
longitudinal lap joint, in accordance with Airbus Service Bulletin 
A320-53-1057, Revision 2, dated July 5, 1996.
    (1) Thereafter, repeat the inspection at one of the following 
intervals:
    (i) If the immediately preceding inspection was conducted using 
visual techniques, conduct the next inspection within 4,000 flight 
cycles.
    (ii) If the immediately preceding inspection was conducted using 
eddy current techniques, conduct the next inspection within 12,000 
flight cycles.
    (2) If any crack is found, prior to further flight, repair in 
accordance with the service bulletin, except as provided by 
paragraph (g) of this AD. Accomplishment of a repair in accordance 
with the service bulletin terminates the repetitive inspection 
requirements for the area repaired.
    (f) Accomplishment of Airbus Modification 21905 in accordance 
with Airbus Service Bulletin A320-53-1056, Revision 02, dated 
February 16, 1998, prior to the accumulation of 20,000 total flight 
cycles constitutes terminating action for the repetitive inspection 
requirements specified in paragraph (e)(1) of this AD.
    (g) If any crack is found during any inspection required by 
paragraph (a), (c), or (e) of 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 
the Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate.
    (h) 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.

    (i) 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 directives 97-314-108(B), 97-313-107(B), and 97-312-
106(B), all dated October 22, 1997.

    Issued in Renton, Washington, on April 7, 1998.

Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-9753 Filed 4-13-98; 8:45 am]
BILLING CODE 4910-13-P