[Federal Register Volume 62, Number 60 (Friday, March 28, 1997)]
[Rules and Regulations]
[Pages 14793-14794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-7517]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-107-AD; Amendment 39-9975; AD 97-07-02]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Airbus Model A300 series airplanes. It 
requires a one-time template inspection of the rear pressure bulkhead 
to detect dents; repetitive eddy current inspections of dents greater 
than a certain depth to detect cracking; and repair, if necessary. This 
amendment is prompted by a report indicating that cracking has been 
found in the vicinity of a dent in the rear pressure bulkhead of one 
airplane. The actions specified by this amendment are intended to 
prevent fatigue cracking resulting from a dent in the rear pressure 
bulkhead; that condition, if not corrected, could reduce the structural 
integrity of the bulkhead and, consequently, lead to rapid 
depressurization of the airplane.

DATES: Effective May 2, 1997.

    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 2, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Airbus Model A300 series 
airplanes was published in the Federal Register on November 5, 1996 (61 
FR 56923). That action proposed to require a one-time template 
inspection of the rear pressure bulkhead to detect dents; repetitive 
eddy current inspections of dented areas greater than a certain depth 
to detect fatigue cracking; and repair, if necessary.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    One commenter supports the proposed AD.

Request to Explain Adequacy of One-Time Inspection

    One commenter asks if a one-time inspection, as would be required 
by the AD, is adequate to address the subject fatigue cracking. The 
commenter points out that if the inspection finds no dents of a depth 
greater than 2 mm, no further action would be required; consequently, 
any subsequent detection of dents/cracking will depend upon the 
existing level and frequency of inspections in the operators' existing 
maintenance program, specifically the Maintenance Planning Document 
(MPD). The commenter questions whether the inspections scheduled under 
the current MPD are adequate to ensure that any small dents are 
subsequently found and corrected in a timely manner.
    The FAA responds to this comment by reiterating the circumstances 
relevant to the cracking addressed by this AD action. The subject 
cracks were detected on the rear pressure bulkhead on one airplane 
during a heavy maintenance check. The cracks were found to initiate 
from a dent in the bulkhead. Airbus conducted analyses and calculations 
of the dent and associated cracking, which demonstrated that:
    1. The force necessary to make a dent of this sort in the rear 
pressure bulkhead in the specific location could not have been 
generated in service, and
    2. The dent was unique to the production process.
    The purpose of the one-time inspection required by this AD is to 
detect dents as small as 2mm in depth in the rear pressure bulkhead 
that may have occurred during production. To accomplish this, the 
inspection makes use of a template in accordance with Airbus Service 
Bulletin A300-53-302, because the inspections conducted under the MPD 
cannot detect small dents of this type. The inspections that are part 
of the MPD are visual inspections, and are considered adequate to 
detect defects of the rear pressure bulkhead that may occur in service.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 15 Airbus Model A300 series airplanes of 
U.S. registry will be affected by this AD, that it will take 
approximately 5 work hours per airplane to accomplish the required 
inspection for denting, and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $4,500, or $300 per airplane.
    If subsequent eddy current inspections to detect cracking are 
necessary, they would require 46 work hours per airplane to accomplish, 
at an average labor rate of $60 per work hour. Based on these figures, 
the cost impact of these inspections on U.S. operators is estimated to 
be $2,760 per airplane per inspection.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.

[[Page 14794]]

    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

97-07-02 Airbus Industrie: Amendment 39-9975. Docket 96-NM-107-AD.

    Applicability: Model A300 airplanes having serial numbers 001 
through 0156, inclusive, 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 (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 prevent fatigue cracking of the rear pressure bulkhead, which 
could reduce its structural integrity, and consequently lead to 
rapid depressurization of the airplane, accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
perform a template inspection to detect dents of the rear pressure 
bulkhead in the area between right hand and left hand radial 
stiffeners RS 5 and RS 13, in accordance with Airbus Service 
Bulletin A300-53-302, dated November 3, 1995.
    (b) If no dent, or if no dent that is greater than 2 mm in 
depth, is detected during the template inspection required by 
paragraph (a) of this AD: No further action is required by this AD.
    (c) If any dent that is greater than 2 mm in depth is detected 
during the template inspection required by paragraph (a) of this AD: 
Prior to further flight, inspect the dent for cracking, in 
accordance with Airbus Service Bulletin A300-53-302, dated November 
3, 1995.
    (1) If no crack is detected: Repeat the inspection for cracking 
at intervals not to exceed 2,000 landings until the permanent repair 
specified in paragraph (c)(1)(i) of this AD is accomplished.
    (i) Prior to the accumulation of 5 years or 11,000 landings 
after the effective date of this AD, whichever occurs first, 
accomplish the permanent repair of the dent in accordance with 
paragraph 2.B.(3)(c)1 of the Accomplishment Instructions of the 
service bulletin.
    (ii) Accomplishment of the permanent repair of the dent 
constitutes terminating action for the repetitive inspection 
requirements of this paragraph, and thereafter, no further action is 
required.
    (2) If only radial cracking is detected in the circumferential 
strap and no other cracking is found elsewhere in the rear pressure 
bulkhead: Prior to further flight, accomplish the circumferential 
strap repair, in accordance with paragraph 2.B.(3)(c)2 of the 
Accomplishment Instructions of the service bulletin. Thereafter, 
inspect the dent for cracking at intervals not to exceed every 1,000 
landings until the permanent repair specified in paragraph (c)(2)(i) 
of this AD is accomplished.
    (i) Prior to the accumulation of 5 years or 11,000 landings 
after the effective date of this AD, whichever occurs first, 
accomplish permanent repair of the dent in accordance with the 
paragraph 2.B.(3)(c)2 of the Accomplishment Instructions of the 
service bulletin.
    (ii) Accomplishment of the permanent repair of the dent 
constitutes terminating action for the repetitive inspection and 
repair requirements of this paragraph and thereafter, no further 
action is required.
    (3) If any other cracking not specified in paragraph (c)(1) or 
(c)(2) of this AD is detected: Prior to further flight, accomplish a 
permanent repair of the dent in accordance with the paragraph 
2.B.(3)(c) 3 or 4, as applicable, of the Accomplishment Instructions 
of the service bulletin; or in a manner approved by the Manager, 
Standardization Branch, ANM-113, FAA, Transport Airplane 
Directorate. Accomplishment of the permanent repair of the dent in 
accordance with the Accomplishment Instructions of the service 
bulletin constitutes terminating action for the requirements of this 
AD and, thereafter, no further action is required.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (e) 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.
    (f) The actions shall be done in accordance with Airbus Service 
Bulletin A300-53-302, dated November 3, 1995. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on May 2, 1997.

    Issued in Renton, Washington, on March 19, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-7517 Filed 3-27-97; 8:45 am]
BILLING CODE 4910-13-U