[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
