[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