[Federal Register Volume 65, Number 66 (Wednesday, April 5, 2000)]
[Proposed Rules]
[Pages 17824-17827]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8391]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-95-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A319, A320, and A321 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Airbus Model A320 
series airplanes, that currently requires an initial inspection of 
fastener holes on certain outer frames of the fuselage to detect 
fatigue cracking, and modification of the area by cold expanding the 
holes and installing oversized fasteners. This action would revise the 
applicability to include additional airplanes; require a high frequency 
eddy current inspection to detect fatigue cracking in the frames and 
frame feet at fuselage frames FR37 through FR41; and follow-on actions. 
This proposal also provides for an optional terminating action for the 
follow-on 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 prevent fatigue cracking of the fuselage frames and frame 
feet, and consequent reduced structural integrity of the fuselage.

DATES: Comments must be received by May 5, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-95-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.

[[Page 17825]]

    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 99-NM-95-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. 99-NM-95-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On May 12, 1997, the FAA issued AD 97-11-01, amendment 39-10030 (62 
FR 28324, May 23, 1997), applicable to certain Airbus Model A320 series 
airplanes, to require an initial inspection of fastener holes on 
certain outer frames of the fuselage to detect fatigue cracking, and 
modification of the area by cold expanding the holes and installing 
oversized fasteners. That action was prompted by a report from the 
manufacturer indicating that, during full-scale fatigue testing of the 
test article, fatigue cracking was detected in the area where the 
center fuselage joins the wing. The requirements of that AD are 
intended to prevent fatigue cracking and consequent reduced structural 
integrity of this area, which could lead to rapid depressurization of 
the fuselage.

Actions Since Issuance of Previous Rule

    The Direction Generale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, has advised the FAA that, during 
accomplishment of the eddy current rotating probe inspection to detect 
fatigue cracking of fastener holes on certain outer frames of the 
fuselage (required by AD 97-11-01), some operators have reported also 
finding cracks in the frame and frame feet at fuselage frames FR37 
through FR41, stringer 23. This condition, if not detected and 
corrected, could result in reduced structural integrity of the 
fuselage.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A320-53-1141, Revision 1, dated 
October 4, 1999. This service bulletin describes procedures for 
conducting a high frequency eddy current (HFEC) inspection to detect 
fatigue cracking in the frames and frame feet at fuselage frames FR37 
through FR41, and follow-on actions. For cases where no cracking is 
detected, the follow-on actions include one of the following: (1) 
Repetitive inspections; (2) the modifications specified in Airbus 
Service Bulletin A320-53-1128 described below; or (3) if applicable, 
modification of certain fastener holes of the fuselage frames FR37 
through FR41 adjacent to stringer 23, and follow-on repetitive 
inspections. For certain cracking conditions, the follow-on actions 
involve a bushing repair, or accomplishment of the modifications in 
Airbus Service Bulletin A320-53-1128. For certain other cracking 
conditions, the follow-on actions involve simultaneous replacement of 
the frame segment or frame foot with a new frame segment or frame foot 
and accomplishment of the modifications in Airbus Service Bulletin 
A320-53-1128.
    Airbus also has issued Service Bulletin A320-53-1128, Revision 01, 
including Appendix 01, both dated October 4, 1999. This service 
bulletin describes procedures for a rotating probe eddy current 
inspection to detect cracks in the fastener holes where the existing 
fasteners are removed; repair of the fastener hole; installation of 
four doublers on each frame; cold working of certain fastener holes; 
installation of new fasteners in the cold-worked holes; and 
installation of new modified system brackets at fuselage frames FR37 
through FR41. These modifications would improve the fatigue strength in 
the frame and frame feet of left and right fuselage frames FR37 through 
FR41, and would eliminate the need for the repetitive HFEC inspections 
in this area.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition. The 
DGAC classified both of these service bulletins as mandatory for 
certain actions, recommended Airbus Service Bulletin A320-53-1128 for 
certain other actions, and issued French airworthiness directive 98-
509-123(B), dated December 16, 1998, in order to assure the continued 
airworthiness of these airplanes in France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 supersede AD 97-11-01 to 
require an HFEC inspection to detect fatigue cracking in the frames and 
frame feet of left and right fuselage frames FR37 through FR41; and 
follow-on actions. This proposal also would allow for an optional 
terminating action for the follow-on repetitive inspections. The 
actions would be required to be accomplished in accordance with the 
service bulletins described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that, unlike the procedures described in 
Airbus Service Bulletin A320-53-1141, this proposed AD would not permit 
further flight if cracks are detected in the frame or frame feet. The 
FAA has determined that, because of the safety implications and 
consequences associated with such cracking, any subject frames or frame 
feet that are found to be cracked must be repaired or modified prior to 
further flight.
    Operators also 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.

Cost Impact

    There are approximately 198 airplanes of U.S. registry that would 
be affected by this proposed AD.
    The new HFEC inspection that is proposed in this AD action would 
take approximately 2 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed requirements of this AD on U.S. operators 
is estimated to be $23,760, or $120 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no

[[Page 17826]]

operator has yet accomplished any of the current or 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 rather than continue the repetitive inspections, it would take 
between 297 and 316 work hours per airplane to accomplish the 
inspection and modification, at an average labor rate of $60 per work 
hour. Required parts would cost between $40 and $5,290 per airplane. 
Based on these figures, the cost impact of this optional terminating 
action is estimated to be between $17,860 and $24,250 per airplane.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 removing amendment 39-10030 (62 FR 
28324, May 23, 1997), and by adding a new airworthiness directive (AD), 
to read as follows:

Airbus Industrie: Docket 99-NM-95-AD. Supersedes AD 97-11-01, 
Amendment 39-10030.

    Applicability: Model A319, A320, and A321 series airplanes, 
certificated in any category; except those on which Airbus 
Modification 25896, 25592, or 25593, or Airbus Service Bulletin 
A320-53-1128, Revision 01, dated October 4, 1999, has been 
accomplished.

    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 (g) 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 prevent fatigue cracking of the fuselage frames and frame 
feet, and consequent reduced structural integrity of the fuselage, 
accomplish the following:

Inspection

    (a) Perform a high frequency eddy current (HFEC) inspection to 
detect fatigue cracks in the frames and frame feet at fuselage 
frames FR37 through FR41, adjacent to stringer 23, at the time 
specified in paragraph (a)(1), (a)(2), or (a)(3), as applicable; in 
accordance with Airbus Service Bulletin A320-53-1141, Revision 01, 
dated October 4, 1999.
    (1) For Configuration 01 airplanes, as identified in Airbus 
Service Bulletin A320-53-1141: Within 3,500 flight cycles after the 
effective date of this AD.
    (2) For Configuration 02 airplanes, as identified in Airbus 
Service Bulletin A320-53-1141: Within 16,000 flight cycles after 
accomplishment of Airbus Service Bulletin A320-53-1025, Revision 1, 
dated November 24, 1994, or within 3,500 flight cycles after the 
effective date of this AD, whichever occurs later.
    (3) For Configurations 03, 04, and 05 airplanes, as identified 
in Airbus Service Bulletin A320-53-1141: Prior to the accumulation 
of 20,000 total flight cycles, or within 3,500 flight cycles after 
the effective date of this AD, whichever occurs later.

Repetitive Inspections or Corrective Action(s)

    (b) For Configuration 01 airplanes: If no crack is detected 
during the HFEC inspection required by paragraph (a) of this AD, 
accomplish the action specified in either paragraph (b)(1) or (b)(2) 
of this AD.
    (1) Repeat the HFEC inspection required by paragraph (a) of this 
AD thereafter at intervals not to exceed 3,500 flight cycles until 
accomplishment of paragraph (f) of this AD. Or
    (2) Prior to further flight, modify each fastener hole of the 
outer frame flanges of left and right fuselage frames FR37 through 
FR41, adjacent to stringer 23, in accordance with Airbus Service 
Bulletin A320-53-1141, Revision 01, dated October 4, 1999. Within 
16,000 flight cycles after accomplishment of this modification, and 
thereafter at intervals not to exceed 3,500 flight cycles, repeat 
the HFEC inspection required by paragraph (a) of this AD until 
accomplishment of paragraph (f) of this AD.

    Note 2: Airbus Service Bulletin A320-53-1141, Revision 01, dated 
October 4, 1999, references Airbus Service Bulletin A320-53-1025, 
Revision 1, dated November 24, 1994, as an additional source of 
information for accomplishing the modification required by paragraph 
(b)(2) of this AD.


    Note 3: Accomplishment of the modification in accordance with 
Airbus Service Bulletin A320-53-1125, dated August 5, 1994, prior to 
the effective date of this AD, is considered acceptable for 
compliance with the modification requirements of paragraph (b)(2) of 
this AD.

    (c) For Configurations 02, 03, 04, and 05 airplanes: If no crack 
is detected during the inspection required by paragraph (a) of this 
AD, repeat the HFEC inspection required by paragraph (a) of this AD 
thereafter at intervals not to exceed 3,500 flight cycles until 
accomplishment of paragraph (f) of this AD.
    (d) If any crack less than 0.20 inches (5.0 mm) in length is 
detected during any HFEC inspection required by this AD, prior to 
further flight, accomplish the actions specified in either paragraph 
(d)(1) or (d)(2) of this AD.
    (1) Repair in accordance with Airbus Service Bulletin A320-53-
1141, Revision 01, dated October 4, 1999. Repeat the HFEC inspection 
required by paragraph (a) of this AD thereafter at intervals not to 
exceed 3,500 flight cycles. Or
    (2) Accomplish the actions specified in paragraph (f) of this 
AD.
    (e) If any crack is 0.20 inches (5.0 mm) or greater in length, 
or if more than one crack per frame side is detected during any HFEC 
inspection required by this AD, prior to further flight, 
simultaneously accomplish the actions specified in paragraphs (e)(1) 
and (e)(2) of this AD.
    (1) Replace the frame segment and/or frame foot with a new frame 
segment or frame foot in accordance with Airbus Service Bulletin 
A320-53-1141, Revision 01, dated October 4, 1999. And
    (2) Accomplish the actions specified in paragraph (f) of this 
AD.

Optional Terminating Action

    (f) Modification of the frames and frame feet area at fuselage 
frames FR37 through FR41 (including the rotating probe eddy current 
inspection to detect cracks, fastener hole repair, installation of 
doublers on each frame, cold working of specified fastener

[[Page 17827]]

holes, installation of new fasteners in the cold-worked holes, and 
installation of new modified system brackets), as applicable, in 
accordance with Airbus Service Bulletin A320-53-1128, Revision 01, 
including Appendix 01, both dated October 4, 1999, constitutes 
terminating action for the requirements of this AD.

    Note 4: Accomplishment of the modification in accordance with 
Airbus Service Bulletin A320-53-1128, including Appendix 1, both 
dated October 3, 1997, prior to the effective date of this AD, is 
considered acceptable for compliance with the modification 
requirements of paragraph (f) of this AD.

Alternative Methods of Compliance

    (g) 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, FAA, 
Transport Airplane Directorate. 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (h) 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 6: The subject of this AD is addressed in French 
airworthiness directive 98-509-123(B), dated December 16, 1998.


    Issued in Renton, Washington, on March 30, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-8391 Filed 4-4-00; 8:45 am]
BILLING CODE 4910-13-U