[Federal Register Volume 61, Number 215 (Tuesday, November 5, 1996)]
[Proposed Rules]
[Pages 56923-56925]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28322]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-107-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A300 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 certain Airbus Model A300 series
airplanes. This proposal would require 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 proposal 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
the proposed AD are intended to prevent fatigue cracking resulting from
a dent in the rear pressure bulkhead, which if uncorrected, could
reduce the structural integrity of the bulkhead, and consequently lead
to rapid depressurization of the airplane.
DATES: Comments must be received by December 16, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-107-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: 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:
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 96-NM-107-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-103, Attention: Rules
Docket No. 96-NM-107-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, recently notified the FAA that an
unsafe condition may exist on certain Airbus Model A300 series
airplanes. The DGAC advises that it has received a report indicating
that cracking caused by fatigue has been detected in the vicinity of a
dent in the rear pressure bulkhead of a Model A300 series airplane; the
cause of the denting has not yet been ascertained, however. Due to the
force required to dent the rear pressure bulkhead, it is likely the
dent did not occur while the airplane was in service, but could have
resulted from a shipping accident prior to installation of the
bulkhead, or from procedures used to install the bulkhead on the
airplane. Furthermore, it is not known if this denting is strictly an
isolated occurrence or if it could affect other Model A300 series
airplanes. What is known, however, is that denting in this area can
lead to cracking which, if not corrected, could reduce the structural
integrity of the rear pressure bulkhead, and consequently lead to rapid
depressurization of the airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin No. A300-53-302, dated November
3, 1995, which describes procedures for conducting a one-time template
inspection of the rear pressure bulkhead to detect dents; conducting
repetitive eddy current inspections of dents greater than a certain
depth to detect fatigue cracking; and repair, if necessary.
Depending on the extent and location of the cracking, the service
bulletin, in some circumstances, provides for continued flight without
immediate repair of the damaged area; temporary and permanent repairs,
however, are to be performed eventually. In other situations, the
service bulletin instructions recommend the installation of a permanent
repair to be performed prior to further flight. The accomplishment of
this permanent repair procedure eliminates the need for repetitive eddy
current inspections and temporary repair.
The DGAC classified this service bulletin as mandatory and issued
French airworthiness directive (CN) 95-245-192(B), dated December 6,
1995, in order to assure the 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
[[Page 56924]]
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.
The FAA acknowledges that additional data is necessary to ascertain
if the denting that was found on the incident airplane was the result
of an isolated event, or if it was the consequence of common shipping
practices, common installation practices, or both. The manufacturer is
continuing its work to determine this. However, regardless of the lack
of data at this time to establish the cause of the denting, the major
consideration in the FAA's decision to promulgate this AD action is the
possibility of dents existing on airplanes throughout the fleet and
going undetected. The concentration of stress in a dented area
increases the likelihood that fatigue cracking will occur. These
cracks, if allowed to propagate, can reduce the structural integrity of
the rear pressure bulkhead, and consequently result in rapid
depressurization of the airplane.
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 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.
The extent and location of cracking would determine whether
temporary or permanent repair is to be accomplished prior to further
flight. In addition, permanent repair would constitute terminating
action for the repetitive eddy current inspections and temporary repair
requirements.
The proposed inspection and certain repairs would be required to be
accomplished in accordance with the service bulletin described
previously.
Differences Between Proposed AD and Relevant Service Information
When radial cracking is detected in the circumferential strap and/
or the rivet area, the service bulletin provides for continued flight
prior to repair. However, the proposed AD would require repair prior to
further flight, regardless of the type of crack or where the cracking
occurs. If radial cracking is detected only in the circumferential
strap, however, a temporary repair would be allowed prior to further
flight; all other cracking in the rear pressure bulkhead would be
required to be permanently repaired before further flight.
Due to the safety implications and consequences associated with
cracking in the rear pressure bulkhead, the FAA has determined that
continued flight without the immediate accomplishment of temporary or
permanent repair, as applicable, is unacceptable.
Cost Impact
The FAA estimates that 15 Airbus Model A300 series airplanes of
U.S. registry would be affected by this proposed AD, that it would take
approximately 5 work hours per airplane to accomplish the proposed
inspection for denting, and that the average labor rate is $60 per work
hour. Based on these figures, the cost impact of the proposed AD on
U.S. operators is estimated to be $4,500, or $300 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.
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:
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 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 No. 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 No. 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
[[Page 56925]]
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 from
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. Issued in Renton,
Washington, on October 29, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-28322 Filed 11-4-96; 8:45 am]
BILLING CODE 4910-13-U
