[Federal Register Volume 63, Number 225 (Monday, November 23, 1998)]
[Proposed Rules]
[Pages 64661-64664]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-31173]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-249-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300 and A300-600 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.


[[Page 64662]]


ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Airbus Model A300 
and A300-600 series airplanes, that currently requires inspections to 
detect cracks in Gear Rib 5 of the main landing gear (MLG) attachment 
fittings at the lower flange, and repair, if necessary. This action 
would establish repetitive inspection intervals for certain inspections 
required by the existing AD. This action also would add a requirement 
to modify Gear Rib 5 of the MLG attachment fittings, which constitutes 
terminating action for 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 fatigue cracking of the MLG 
attachment fittings, which could result in reduced structural integrity 
of the airplane.

DATES: Comments must be received by December 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-249-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 Docket Number 98-NM-249-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. 98-NM-249-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 23, 1998, the FAA issued AD 98-03-06, amendment 39-10298 
(63 FR 5224, February 2, 1998), applicable to certain Airbus Model A300 
and A300-600 series airplanes, to require inspections to detect cracks 
in Gear Rib 5 of the main landing gear (MLG) attachment fittings at the 
lower flange, and repair, if necessary. That action was prompted by 
issuance of mandatory continuing airworthiness information by a foreign 
civil airworthiness authority. The requirements of that AD are intended 
to detect and correct fatigue cracking of the MLG attachment fittings, 
which could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    Since the issuance of AD 98-03-06, the manufacturer has issued 
Airbus Service Bulletins A300-57-0234, Revision 01 (for Model A300 
series airplanes), and A300-57-6087, Revision 01 (for Model A300-600 
series airplanes), both dated March 11, 1998. Airbus Service Bulletin 
A300-57-0234, Revision 01, limits the effectivity of the existing AD, 
however, these service bulletins add no additional airplanes to the 
effectivity. These service bulletins recommend repetitive intervals for 
accomplishing detailed visual and high frequency eddy current 
inspections to detect cracks in Gear Rib 5 of the main landing gear 
(MLG) attachment fittings at the lower flange. The Direction Generale 
de l'Aviation Civile (DGAC), which is the airworthiness authority for 
France, classified these service bulletins as mandatory and issued 
French airworthiness directive 98-151-247(B), dated April 8, 1998, in 
order to assure the continued airworthiness of these airplanes in 
France.
    The manufacturer also has issued Airbus Service Bulletins A300-57-
0235 (for Model A300 series airplanes), and A300-57-6088 (for Model 
A300-600 series airplanes), both dated August 5, 1998. These service 
bulletins describe procedures for modification of Gear Rib 5 of the MLG 
attachment fittings at the lower flange by increasing the depth, 
diameter, and corner radius of the spotface of specified fastener 
holes. Accomplishment of this modification would eliminate the need for 
the repetitive inspections described previously. The DGAC approved 
these service bulletins.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 supersede AD 98-03-06 to 
continue to require inspections to detect cracks in Gear Rib 5 of MLG 
attachment fittings at the lower flange, and repair, if necessary. The 
proposed AD also would establish repetitive inspection intervals for 
certain inspections. In addition, the proposal would require 
modification of Gear Rib 5 of the MLG attachment fittings, which 
constitutes terminating action for the repetitive inspections. The 
actions would be required to be accomplished in accordance with the

[[Page 64663]]

service bulletins described previously, except as discussed below.

Differences Between the Proposed AD and the Related Service 
Bulletins

    Operators should note that, although the service bulletins 
described previously specify that appropriate corrective action may be 
obtained by contacting the manufacturer for disposition of certain 
repair conditions, this proposal would require that any such repairs be 
accomplished in accordance with a method approved by either the FAA or 
the Direction Generale de l'Aviation Civile (or its delegated agent).
    Operators also should note that this AD proposes to mandate, prior 
to the accumulation of 21,000 total flight cycles or within 2 years 
after the effective date of the AD, whichever occurs later, the 
modification of Gear Rib 5 of the MLG attachment fittings as described 
in Airbus Service Bulletins A300-57-6088 and A300-57-0235. 
Accomplishment of this modification would constitute terminating action 
for the repetitive inspections.
    The FAA has determined that long-term continued operational safety 
will be better assured by modifications or 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 repetitive 
inspections, has led the FAA to consider placing less emphasis on 
special procedures and more emphasis on design improvements. The 
proposed modification requirement is in consonance with these 
considerations.

Cost Impact

    There are approximately 164 airplanes of U.S. registry that would 
be affected by this proposed AD.
    The inspection currently required by AD 98-03-06, and retained in 
this proposed AD, takes approximately 6 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the currently required inspection on 
U.S. operators is estimated to be $59,040, or $360 per airplane, per 
inspection cycle.
    The modification that is proposed in this AD action would take 
approximately 62 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $10,270 per airplane. Based on these figures, the cost 
impact of the new actions proposed by this AD on U.S. operators is 
estimated to be $2,294,360, or $13,990 per airplane.
    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 39-10298 (63 FR 
5224, February 2, 1998), and by adding a new airworthiness directive 
(AD), to read as follows:

Airbus Industrie: Docket 98-NM-249-AD. Supersedes AD 98-03-06, 
Amendment 39-10298.

    Applicability: Model A300 series airplanes, as listed in Airbus 
Service Bulletin A300-57-0234, Revision 01, dated March 11, 1998; 
and Model A300-600 series airplanes, as listed in Airbus Service 
Bulletin A300-57-6087, Revision 01, dated March 11, 1998; 
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 (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 fatigue cracking of the main landing gear (MLG) 
attachment fittings, which could result in reduced structural 
integrity of the airplane, accomplish the following:
    (a) For Model A300 series airplanes that have accumulated more 
than 27,000 flight cycles as of March 9, 1998 (the effective date of 
AD 98-03-06, amendment 39-10298): Except as provided by paragraph 
(b) of this AD, within 40 flight cycles after March 9, 1998, perform 
a detailed visual inspection to detect cracks in Gear Rib 5 of the 
MLG attachment fittings at the lower flange, in accordance with 
Airbus Service Bulletin A300-57-0234, Revision 01, dated March 11, 
1998. Thereafter, repeat the inspection at intervals not to exceed 
40 flight cycles, until the initial inspections required by 
paragraph (b) are accomplished.
    (b) For all airplanes: Perform a detailed visual and a high 
frequency eddy current (HFEC) inspection to detect cracks in Gear 
Rib 5 of the MLG attachment fittings at the lower flange, in 
accordance with Airbus Service Bulletin A300-57-6087, Revision 01, 
dated March 11, 1998 (for Model A300-600 series airplanes); or A300-
57-0234, Revision 01, dated March 11, 1998 (for Model A300 series 
airplanes); as applicable; at the time specified in paragraph (b)(1) 
or (b)(2) of this AD, as applicable. Repeat the inspections 
thereafter at intervals not to exceed 1,500 flight cycles. 
Accomplishment of the inspections required by this paragraph 
terminates the inspections required by paragraph (a) of this AD.
    (1) For airplanes that have accumulated 20,000 or more total 
flight cycles as of March 9, 1998: Inspect within 500 flight cycles 
after March 9, 1998.
    (2) For airplanes that have accumulated less than 20,000 total 
flight cycles as of March 9, 1998: Inspect prior to the

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accumulation of 18,000 total flight cycles, or within 1,500 flight 
cycles after March 9, 1998, whichever occurs later.

    Note 2: Accomplishment of the initial detailed visual and HFEC 
inspections in accordance with Airbus Service Bulletin A300-57A0234 
or A300-57A6057, both dated August 5, 1997, as applicable, is 
considered acceptable for compliance with the initial inspections 
required by paragraph (a) or (b) of this AD.

    (c) If any crack is detected during any inspection required by 
this AD, prior to further flight, repair in accordance with a method 
approved by the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate, or the Direction Generale de 
l'Aviation Civile (or its delegated agent).
    (d) Prior to the accumulation of 21,000 total flight cycles, or 
within 2 years after the effective date of this AD, whichever occurs 
later: Modify Gear Rib 5 of the MLG attachment fittings at the lower 
flange in accordance with Airbus Service Bulletin A300-57-6088 (for 
Model A300-600 series airplanes), or A300-57-0235 (for Model A300 
series airplanes), both dated August 5, 1998, as applicable. 
Accomplishment of this modification constitutes terminating action 
for the repetitive inspection requirements of this AD.
    (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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (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 4: The subject of this AD is addressed in French 
airworthiness directive 98-151-247 (B), dated April 8, 1998.

    Issued in Renton, Washington, on November 16, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-31173 Filed 11-20-98; 8:45 am]
BILLING CODE 4910-13-U