[Federal Register Volume 62, Number 117 (Wednesday, June 18, 1997)]
[Proposed Rules]
[Pages 33040-33043]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-15887]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-200-AD]
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 supersedure of an existing
airworthiness directive (AD), applicable to all Airbus Industrie Model
A300-600 series airplanes, that currently requires inspections to
detect cracks in the center spar sealing angles adjacent to the pylon
rear attachment and in the adjacent butt strap and skin panel, and
corrections of discrepancies. That AD was prompted by reports of
cracking in the vertical web of the center spar sealing angles of the
wing. This action would require that the initial inspections be
accomplished at reduced
[[Page 33041]]
thresholds. This action also would limit the applicability of the
existing AD. The actions specified by the proposed AD are intended to
prevent crack formation in the sealing angles; such cracks could
rupture and lead to subsequent crack formation in the bottom skin of
the wing, and resultant reduced structural integrity of the center spar
section of the wing.
DATES: Comments must be received by July 28, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-200-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: Charles D. Huber, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2589; 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 Docket Number 95-NM-200-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. 95-NM-200-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On November 17, 1993, the FAA issued AD 93-23-07, amendment 39-8741
(58 FR 64112, December 6, 1993), applicable to all Airbus Model A300-
600 series airplanes, to require inspections to detect cracks in the
center spar sealing angles adjacent to the pylon rear attachment and in
the adjacent butt strap and skin panel, and corrections of any
discrepancies. That action was prompted by reports of cracking in the
vertical web of the center spar sealing angles of the wing. The
requirements of that AD are intended to prevent crack formation in the
sealing angles; such cracks could rupture and lead to subsequent crack
formation in the bottom skin of the wing, and resultant reduced
structural integrity of the center spar section of the wing.
Actions Since Issuance of the Previous AD
Since the issuance of that AD, the manufacturer has advised the FAA
that it has received additional reports of cracking in the vertical web
of the center spar sealing angles of the wing. The reports indicated
that the airplanes on which this cracking had been detected had
accumulated between 5,540 and 21,200 landings and between 11,616 and
21,250 flight hours. These numbers of landings are less than those
identified as the initial inspection threshold in AD 93-23-07.
Explanation of Relevant Service Information
Subsequent to the findings of this new cracking, Airbus issued
Service Bulletin A300-57-6027, Revision 2, dated September 13, 1994.
The revised service bulletin recommends that the initial inspection
threshold be reduced. Revision 2 of the service bulletin also limits
the effectivity to airplanes having certain manufacturer's serial
numbers. The DGAC classified this service bulletin as mandatory and
issued French airworthiness directive 91-253-128(B)R1, dated March 1,
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
Sec. 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 the Requirements of the Proposed AD
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 supersede AD 93-23-07 to
continue to require inspections to detect cracks in the center spar
sealing angles adjacent to the pylon rear attachment and in the
adjacent butt strap and skin panel, and corrections of discrepancies.
This proposed AD would reduce the initial inspection thresholds; and
limit the applicability of the existing AD to certain airplanes. The
actions would be required to be accomplished in accordance with the
service bulletin described previously.
Differences Between the Proposed Rule and Relevant Service
Information
Operators should note that, unlike the procedures described in
Airbus Service Bulletin A300-57-6027, this proposed AD would not permit
further flight if cracking of the center spar sealing angles adjacent
to Rib 8 is detected. The FAA has determined that, due to the safety
implications and consequences associated with such cracking, center
spar sealing angles that are found to be cracked must be replaced prior
to further flight.
Operators also should note that, unlike particular provisions in
the service bulletin regarding adjustment of the compliance times, this
proposed AD would permit certain adjustments of the inspection
compliance times only with prior approval by the FAA. The FAA has
determined that, in some cases, such adjustments would not address the
unsafe condition in a timely manner.
[[Page 33042]]
Additionally, such adjustments may present difficulties in determining
if the applicable inspections and modifications have been complied with
in the appropriate time frame. In developing the appropriate inspection
thresholds and repetitive inspection intervals for the proposed rule,
the FAA considered the manufacturer's recommendation and the average
utilization rate of the affected U.S. registered airplanes. In light of
these factors, the FAA finds the compliance times specified in the
proposed AD to be warranted. However, operators may request approval of
an adjustment to the compliance time under the provisions of paragraph
(g) of this proposed AD provided that such an adjustment provides an
acceptable level of safety.
Cost Impact
There are approximately 34 Model A300-600 series airplanes of U.S.
registry that would be affected by this proposed AD.
The requirements of this proposed AD will not add any new
additional economic burden on affected operators, other than the costs
that are associated with the initial inspection being required earlier
than would have been required by AD 93-23-07 (inspection is now
required within 4,638 total landings, rather than 12,000 total
landings, for certain airplanes; and within 5,775 landings, rather than
15,000 total landings, for certain other airplanes). The current costs
associated with AD 93-23-07 are reiterated in their entirety (as
follows) for the convenience of affected operators.
The costs associated with the currently required inspections entail
8 work hours per airplane, per inspection, at an average labor rate of
$60 per work hour. (This figure does not include the time necessary for
gaining access and closing up.) Based on these figures, the cost impact
of this proposed AD on U.S. operators is estimated to be $16,320, or
$480 per airplane, per inspection.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the current or 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 removing amendment 39-8741 (58 FR
64112, December 6, 1993), and by adding a new airworthiness directive
(AD), to read as follows:
Airbus: Docket 95-NM-200-AD. Supersedes AD 93-23-07, Amendment
39-8741.
Applicability: Model A300-600 series airplanes, as listed in
Airbus Service Bulletin A300-57-6027, Revision 2, dated September
13, 1994; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
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 (g) 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.
Note 2: Paragraphs (a) and (b) of this AD restate the
requirements for initial and repetitive inspections contained in
paragraph (a) and (c) of AD 93-23-07. Therefore, for operators who
have previously accomplished at least the initial inspection in
accordance with AD 93-23-07, paragraphs (a) and (b) of this AD
require that the next scheduled inspection be performed within 2,625
landings after the last inspection performed in accordance with
paragraph (a) or (c) of AD 93-23-07, or within 500 landings after
the effective date of this AD, whichever occurs later.
To prevent crack formation in the sealing angles, which could
rupture and lead to subsequent crack formation in the bottom skin of
the wing, and resultant reduced structural integrity of the center
spar section of the wing, accomplish the following:
Restatement of the Requirements of AD 93-23-07
(a) For those airplanes on which the modification described in
Airbus Repair Drawing R571-40588 has not been accomplished: Perform
high frequency eddy current (HFEC) inspections to detect cracks in
the center spar sealing angles adjacent to Rib 8, in accordance with
Airbus Industrie Service Bulletin No. A300-57-6027, dated October 8,
1991, or Revision 2, dated September 13, 1994, at the time specified
in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable.
After the effective date of this AD, only Revision 2 of the service
bulletin shall be used.
(1) For airplanes that have accumulated less than 12,000 total
landings as of January 5, 1994 (the effective date of AD 93-23-07,
amendment 39-8741): Prior to the accumulation of 12,000 total
landings or within 2,000 landings after January 5, 1994, whichever
occurs later; and thereafter at intervals not to exceed 6,000
landings until the inspections required by paragraph (c) of this AD
are accomplished.
(2) For airplanes that have accumulated 12,000 total landings or
more, but less than 14,000 total landings as of January 5, 1994:
Prior to the accumulation of 14,000 total landings or within 2,000
landings after January 5, 1994, whichever occurs later; and
thereafter at intervals not to exceed 6,000 landings until the
inspections required by paragraph (c) of this AD are accomplished.
(3) For airplanes that have accumulated 14,000 total landings or
more as of January 5, 1994: Prior to the accumulation of 500
landings after January 5, 1994; and thereafter at intervals not to
exceed 6,000 landings until the inspections required by paragraph
(c) of this AD are accomplished.
(b) For those airplanes on which the modification specified in
Airbus Repair Drawing R571-40588 has been accomplished: Prior to the
accumulation of 15,000 landings after accomplishing the
modification, or within 500 landings after January 5, 1994,
whichever occurs later, perform a HFEC inspection to detect cracks
in the center spar sealing angles adjacent to
[[Page 33043]]
Rib 8, in accordance with Airbus Industrie Service Bulletin No.
A300-57-6027, dated October 8, 1991, or Revision 2, dated September
13, 1994. Thereafter, repeat this inspection at intervals not to
exceed 6,000 landings until the inspection required by paragraph (d)
of this AD is accomplished.
New Requirements of this AD
(c) For those airplanes on which Airbus modification 08609H5276
(Airbus Service Bulletin A300-57-6033), or the modification
specified in Airbus Repair Drawing R571-40588 or R571-40942, has not
been accomplished: Perform HFEC inspections to detect cracks in the
center spar sealing angles adjacent to Rib 8, in accordance with
Airbus Service Bulletin A300-57-6027, Revision 2, dated September
13, 1994, at the later of the times specified in paragraph (a)(1)
and (a)(2) of this AD, as applicable. Repeat the inspection
thereafter at intervals not to exceed 2,625 landings. Accomplishment
of these inspections terminates the requirements of paragraph (a) of
this AD.
(1) For airplanes on which HFEC inspections have not been
accomplished in accordance with AD 93-23-07: Prior to the
accumulation of 4,638 total landings; or within 500 landings after
the effective date of this AD, whichever occurs later.
(2) For airplanes on which HFEC inspections have been
accomplished in accordance with AD 93-23-07: Within 2,625 landings
after accomplishment of the last inspection performed in accordance
with the requirements of paragraph (a) of this AD, or within 500
landings after the effective date of this AD, whichever occurs
later.
(d) For those airplanes on which Airbus Modification 08609H5276
(Airbus Service Bulletin A300-57-6033) or the modification specified
in Airbus Repair Drawing R571-40588 or R571-40942 has been
accomplished: Perform a HFEC inspection to detect cracks in the
center spar sealing angles adjacent to Rib 8, in accordance with
Airbus Service Bulletin No. A300-57-6027, Revision 2, dated
September 13, 1994, at the later of the times specified in
paragraphs (d)(1) and (d)(2) of this AD, as applicable. Repeat the
inspection thereafter at intervals not to exceed 2,625 landings.
Accomplishment of this inspection terminates the requirements of
paragraph (b) of this AD.
(1) For airplanes on which HFEC inspections have not been
accomplished in accordance with AD 93-23-07: Prior to the
accumulation of 5,775 landings after accomplishing the modification,
or within 500 landings after the effective date of this AD.
(2) For airplanes on which HFEC inspections have been
accomplished in accordance with AD 93-23-07: Within 2,625 landings
after accomplishment of the last inspection performed in accordance
with the requirements of paragraph (b) of this AD, or within 500
landings after the effective date of this AD, whichever occurs
later.
Corrective Action
(e) If any crack is found in the center spar sealing angles,
including cracking entirely through the sealing angle, during the
inspections required by paragraph (a), (b), (c), or (d) of this AD:
Prior to further flight, replace the pair of sealing angles on the
affected wing and cold work the attachment holes, in accordance with
Airbus Repair Drawing R571-40589 or R571-40942; and perform the
repetitive inspections required by paragraph (c) or (d) of this AD,
as applicable.
(f) If any sealing angle is found to be cracked through entirely
during the inspections required by paragraph (a), (b), (c), or (d)
of this AD: Prior to further flight, perform additional inspections
to detect cracks in the adjacent butt strap and skin panel, in
accordance with paragraph 2.B.(5) of Airbus Service Bulletin A300-
57-6027, Revision 2, dated September 13, 1994. If any crack is found
in the adjacent butt strap and skin panel, prior to further flight,
repair in accordance with Airbus Repair Drawing R571-40611.
(g)(1) 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.
(2) Operators may request an extension of the compliance times
of this AD in accordance with the adjustment for range formula found
in paragraph 1(d) of Airbus Service Bulletin A300-57-6027, Revision
2, dated September 13, 1994. The average flight time per flight
cycle in hours used in this formula should be for an individual
airplane. Average flight time for a group of airplanes may be used
if all airplanes in the group have flight times differing by no more
than 10 percent. If compliance times are based on the average flight
time for a group of airplanes, the individual airplane flight times
of the group must be submitted to the Manager, Standardization
Branch, ANM-113, for review.
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.
(h) 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 July 11, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-15887 Filed 6-17-97; 8:45 am]
BILLING CODE 4910-13-U
