[Federal Register Volume 62, Number 58 (Wednesday, March 26, 1997)]
[Proposed Rules]
[Pages 14361-14363]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-7681]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-182-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Industrie Model A300-600 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 Industrie Model
A300-600 series airplanes. This proposal would require repetitive eddy
current inspections to detect cracks of the outer skin of the fuselage
at certain frames, and repair or reinforcement of the structure at the
frames, if necessary. This proposal also would require eventual
reinforcement of the structure at certain frames, which, when
accomplished, terminates the repetitive inspections. This proposal is
prompted by a report indicating that fatigue cracks were found in the
area of certain frames. The actions specified by the proposed AD are
intended to prevent such fatigue cracking, which could reduce the
structural integrity of the airframe and result in rapid decompression
of the airplane.
DATES: Comments must be received by May 5, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-182-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-182-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-182-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 Model A300-600 series airplanes.
The DGAC advises that, during inspection of in-service Model A300
series airplanes, fatigue cracks were found after 18,000 flight cycles
in the area of frames 28A and 30A, at left and right-hand stringer 30.
Fatigue cracking in this area of the fuselage could reduce the
structural integrity of the airframe and result in rapid decompression
of the airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A300-53-6045, dated March 21,
1995, as revised by Change Notice No. O.A., dated June 1, 1995, which
describes procedures for repetitive eddy current inspections to detect
cracks of the outer skin of the fuselage at frames 28A and 30A above
stringer 30, and repair or reinforcement of the structure of the
frames, if necessary.
Airbus also has issued Service Bulletin A300-53-6037, dated March
21, 1995, which describes procedures for reinforcement of the structure
at frames 28 and 29, and frames 30 and 31, between stringers 29 and 30.
Accomplishment of the reinforcement will limit the risk of cracking in
these areas. Such reinforcement eliminates the need for the repetitive
inspections.
The DGAC classified Airbus Service Bulletin A300-53-6045 as
mandatory and issued French airworthiness directive (C/N) 95-244-
191(B), dated December 6, 1995, in order to assure the continued
airworthiness of these airplanes in France. The DGAC
[[Page 14362]]
classified Airbus Service Bulletin A300-53-6037 as recommended.
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 repetitive eddy
current inspections to detect cracks of the outer skin of the fuselage
at frames 28A and 30A above stringer 30; and repair or reinforcement of
the structure of the frames, if necessary. Additionally, the proposed
AD would require eventual reinforcement of the structure at frames 28
and 29, and frames 30 and 31, between stringers 29 and 30.
Accomplishment of this reinforcement constitutes terminating action for
the repetitive inspections. The actions would be required to be
accomplished in accordance with the service bulletins described
previously.
Differences Between Proposed Rule and Service Bulletins
Operators should note that, unlike the procedures described in
Airbus Service Bulletins A300-53-6045 and A300-53-6037, this proposed
AD would not permit further flight if cracks are detected in the outer
skin. The FAA has determined that, because of the safety implications
and consequences associated with such cracking, any subject outer skin
that is found to be cracked must be repaired or modified prior to
further flight.
Operators should also note that the proposed AD would differ from
Airbus FL Service Bulletin A300-53-6045 in that it would require the
initial eddy current inspection to be accomplished prior to the
accumulation of 14,100 total flight cycles, or within 12 months of the
effective date of the AD, whichever occurs later. (The service bulletin
recommends inspection prior to the accumulation of 18,000 flight
cycles, or at the next ``C'' check, whichever occurs first.) In
developing an appropriate compliance time for this action, the FAA
considered not only the degree of urgency associated with addressing
the subject unsafe condition, but the susceptibility of the outer skin
of the fuselage to fatigue cracking, which could result in rapid
decompression of the airplane. The FAA has also received reports of
fatigue cracking on affected airplanes that had accumulated as few as
14,100 total flight cycles. In consideration of these items, the FAA
finds that the initial eddy current inspection conducted at the
proposed compliance time stated previously will better ensure that any
detrimental effect associated with fatigue cracking will be identified
and corrected prior to the time that it could adversely affect the
outer skin of the fuselage.
Operators should also note that this AD proposes to mandate, within
5 years, the reinforcement described in Service Bulletin A300-53-6037
as terminating action for the repetitive inspections. [Incorporation of
this terminating action of this service bulletin is optional in the
French C/N 95-244-191(B).] The FAA has determined that long-term
continued operational safety will be better assured by design changes
to remove the source of the problem, rather than by repetitive
inspections. Long-term inspections may not be providing the degree of
safety assurance necessary for the transport airplane fleet.
This, coupled with a better understanding of the human factors
associated with numerous continual inspections, has led the FAA to
consider placing less emphasis on inspections and more emphasis on
design improvements. The proposed reinforcement requirement is in
consonance with these conditions.
Cost Impact
The FAA estimates that 34 Airbus Model A300-600 series airplanes of
U.S. registry would be affected by this proposed AD.
The eddy current inspection that is proposed by this AD would take
approximately 1 work hour per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the proposed inspection on U.S. operators is estimated to be
$2,040, or $60 per airplane, per inspection cycle.
The reinforcement that is proposed in this AD would take
approximately 93 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Required parts would cost
approximately $7,200 per airplane. Based on these figures, the cost
impact of the proposed modification requirements of this AD on U.S.
operators is estimated to be $434,520, or $12,780 per airplane.
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.
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-182-AD.
[[Page 14363]]
Applicability: Model A300-600 series airplanes on which Airbus
Modification 8683 was not accomplished during production, or on
which Airbus Modification 8684 has not been installed; certificated
in any category.
Note 1: Airbus Models A300 B2 and B4 series airplanes are not
subject to the requirements of this AD.
Note 2: 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 (c) 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 outer skin at frames
28A and 30A, which could reduce the structural integrity of the
airframe and result in rapid decompression of the airplane,
accomplish the following actions:
(a) Prior to the accumulation of 14,100 total flight cycles, or
within 12 months after the effective date of the AD, whichever
occurs later, conduct an eddy current inspection to detect cracking
of the fuselage outer skin at frames 28A and 30A above stringer 30,
in accordance with Airbus Service Bulletin A300-53-6045, dated March
21, 1995, as revised by Change Notice No. O.A., dated June 1, 1995.
(1) If no cracking is found, repeat the inspection thereafter at
intervals not to exceed 4,500 flight cycles.
(2) If any cracking is found that is within the limits specified
in the service bulletin, repair in accordance with paragraph 2.D. of
the Accomplishment Instructions of Airbus Service Bulletin A300-53-
6045, dated March 21, 1995, as revised by Change Notice No. O.A.,
dated June 1, 1995; or reinforce the structure at frames 28 and 29,
and at frames 30 and 31, between stringers 29 and 30, in accordance
with Airbus Service Bulletin A300-53-6037, dated March 21, 1995.
1(i) If the repair is accomplished: After the repair, repeat the
eddy current inspection thereafter at intervals not to exceed 4,500
flight cycles.
(ii) If the reinforcement is accomplished: Such reinforcement
constitutes terminating action for the repetitive inspections
required by this AD.
(3) If any cracking is found that is outside the limits
specified in the service bulletin, prior to further flight,
reinforce the structure at frames 28 and 29, and at frames 30 and
31, between stringers 29 and 30, in accordance with Airbus Service
Bulletin A300-53-6037, dated March 21, 1995. Such reinforcement
constitutes terminating action for the repetitive inspections
required by this AD.
(b) Within 5 years after the effective date of this AD,
reinforce the structure at frames 28 and 29, and at frames 30 and
31, between stringers 29 and 30, in accordance with Airbus Service
Bulletin A300-53-6037, dated March 21, 1995. Such reinforcement
constitutes terminating action for the repetitive inspections
required by this AD.
(c) 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(d) 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 March 20, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-7681 Filed 3-25-97; 8:45 am]
BILLING CODE 4910-13-U
