[Federal Register Volume 63, Number 42 (Wednesday, March 4, 1998)]
[Proposed Rules]
[Pages 10576-10579]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-5605]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-153-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus 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 Model A300-600
series airplanes. This proposal would require repetitive inspections to
detect cracks in the angle fitting at frame 40 of the center wing box,
and corrective actions, if necessary; and eventual modification of that
angle fitting, which would terminate the 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 cracks in the
center wing box angle fitting, which could result in the failure of the
center wing box at frame 40, and consequent reduced structural
integrity of the airplane.
DATES: Comments must be received by April 3, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-153-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.
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
[[Page 10577]]
Docket Number 97-NM-153-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. 97-NM-153-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, notified the FAA that an unsafe
condition may exist on certain Airbus Model A300-600 series airplanes.
The DGAC advises that, during inspections of the lower outboard radius
of frame 40 on Model A300 series airplanes, operators have found 30
cases of cracking in this area. The cracking originated in a fastener
hole. Based on design similarity, analysis has shown that cracking also
could occur in this area on Model A300-600 series airplanes. This
condition, if not detected and corrected in a timely manner, could
result in the failure of the center wing box at frame 40, and
consequent reduced structural integrity of the airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A300-57-6052, Revision 1, dated
July 22, 1996, which describes procedures for repetitive inspections to
detect cracks in the angle fitting at frame 40 of the center wing box,
and follow-on corrective actions, if necessary. The follow-on
corrective actions include repetitive eddy current inspections, and
temporary repair of the area prior to accomplishment of a permanent
modification.
Airbus also has issued Service Bulletin A300-57-6053, Revision 1,
dated October 31, 1995, which describes procedures for a modification
to the angle fitting at frame 40, which would eliminate the need for
the repetitive inspections. The modification involves the installation
of new angle fittings and taper-lok fasteners. Accomplishment of the
actions specified in this service bulletin is intended to adequately
address the identified unsafe condition.
The DGAC classified Airbus Service Bulletin A300-57-6052, Revision
1, dated July 22, 1996, as mandatory and issued French airworthiness
directive (CN) 95-111-181(B)R1, dated October 23, 1996, 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 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 accomplishment of
the actions specified in the service bulletins described previously,
except as discussed below.
Differences Between the Proposed Rule and the Related Service
Bulletin
The proposed rule would differ from Airbus Service Bulletin A300-
57-6052 in that, unlike the compliance time thresholds and intervals
provided in the service bulletin, this proposed AD would require
accomplishment of the actions at compliance time thresholds and
intervals based on the Average Flight Time (AFT) of the airplane, as
specified in Table 1 of this AD. The threshold and intervals defined in
the service bulletin are based on an AFT of 125 minutes. For airplanes
that are operated with different flight durations, adjustments must be
made to the thresholds and intervals. To provide clarification of the
appropriate thresholds and intervals, Table 1 has been included in this
proposed AD. The thresholds and intervals provided in Table 1 have been
adjusted for various AFT's.
The proposed rule also would differ from the service bulletin in
that the service bulletin recommends the visual inspection be
accomplished with or without the nut removed, while this proposed AD
requires that any inspection, whether visual, eddy current, or liquid
penetrant, be performed with the nut removed. The FAA has determined
that, without removal of the nut, a visual inspection technique is not
an appropriate method of compliance with the proposed AD, due to the
time required to gain access to the area to be inspected and the
necessity to perform frequent subsequent inspections if the inspection
is done without removal of the nut.
Operators should also note that, unlike the procedures described in
the service bulletin, this proposed AD would not permit further flight
with cracking detected in the forward angle fitting of frame 40. The
FAA has determined that, due to the safety implications and
consequences associated with such cracking, all fittings that are found
to be cracked must be replaced prior to further flight.
Further, although the service bulletin specifies that the
manufacturer may be contacted for disposition of certain repair
conditions, this proposal would require the repair of those conditions
to be accomplished in accordance with a method approved by the FAA.
Additionally, operators should note that this AD proposes to
mandate, within 4 years after the effective date of this AD, the
modification described in Airbus Service Bulletin A300-57-6053,
Revision 1, dated October 31, 1995, as terminating action for the
repetitive inspections. (Incorporation of the terminating action
specified in this service bulletin is optional in French airworthiness
directive 95-111-181(B) R1, dated October 23, 1996.) 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 modification requirement is in
consonance with these conditions.
Cost Impact
The FAA estimates that 54 Model A300-600 series airplanes of U.S.
registry would be affected by this proposed AD.
It would take approximately 36 work hours per airplane to
accomplish the proposed inspection, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the inspection
proposed by this AD on U.S. operators is estimated to be $116,640, or
$2,160 per airplane, per inspection cycle.
It would take approximately 754 work hours per airplane to
accomplish the proposed modification, at an average labor rate of $60
per work hour. Required parts would cost
[[Page 10578]]
approximately $11,605 per airplane. Based on these figures, the cost
impact of the modification proposed by this AD on U.S. operators is
estimated to be $3,069,630, or $56,845 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: Docket 97-NM-153-AD.
Applicability: Model A300-600 series airplanes on which Airbus
Modification 10453 has not been installed; 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 (e) 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 cracks in the center wing box angle fitting, which
could result in the failure of the center wing box at frame 40, and
consequent reduced structural integrity of the airplane, accomplish
the following:
(a) Prior to the accumulation of the threshold specified in
Table 1 of this AD, as applicable, or within 1,500 flight cycles
after the effective date of this AD, whichever occurs later: Perform
a detailed visual, eddy current, or liquid penetrant inspection to
detect cracking in the angle fitting of frame 40 (both left and
right), with the nut removed, in accordance with Airbus Service
Bulletin A300-57-6052, Revision 1, dated July 22, 1996. Thereafter,
repeat the inspections at the interval specified in Table 1 of this
AD, as applicable, until the actions required by paragraph (c) of
this AD have been accomplished.
Table 1
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Eddy
current/
Visual liquid
Average flight time (AFT): Flight Threshold inspection penetrant
hours/flight cycles (flight interval inspection
cycles) (flight interval
cycles) (flight
cycles)
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2.10-2.49........................ 5,900 4,700 6,300
2.50-2.99........................ 5,600 4,400 4,900
3.00-3.49........................ 5,200 4,100 4,600
3.50-3.99........................ 4,800 3,800 4,200
4.00-4.49........................ 4,400 3,500 3,900
4.50-4.99........................ 4,000 3,200 3,500
5.00-5.49........................ 3,600 2,800 3,200
5.50-5.99........................ 2,300 2,500 2,800
6.00-6.50........................ 2,800 2,200 2,500
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(b) Except as provided by paragraph (d) of this AD, if any crack
is found during an inspection required by paragraph (a) of this AD,
prior to further flight, accomplish follow-on corrective actions in
accordance with the procedures specified in Airbus Service Bulletin
A300-57-6052, Revision 1, dated July 22, 1996.
(c) Within 4 years after the effective date of this AD, modify
the angle fitting at frame 40 (both left and right) in accordance
with Airbus Service Bulletin A300-57-6053, Revision 1, dated October
31, 1995. Accomplishment of the modification constitutes terminating
action for the repetitive inspections required by paragraph (a) of
this AD.
(d) If any crack is found during an inspection required by
paragraph (a) of this AD, and the applicable service bulletin
specifies to contact the manufacturer for an appropriate action:
Prior to further flight, repair in accordance with a method approved
by the Manager, International Branch, ANM-116, FAA, Transport
Airplane Directorate.
(e) 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.
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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
[[Page 10579]]
(f) 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.
Note 3: The subject of this AD is addressed in French
airworthiness directive (CN) 95-111-181(B) R1, dated October 23,
1996.
Issued in Renton, Washington, on February 26, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-5605 Filed 3-3-98; 8:45 am]
BILLING CODE 4910-13-U
