[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)]
[Proposed Rules]
[Pages 15441-15443]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8253]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-215-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A300, A300-600, and A310
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 all Airbus Model A300, A300-600,
and A310 series airplanes. This proposal would require inspecting the
bearings located in the mechanical control linkage of the nose landing
gear (NLG) free-fall mechanism for discrepancies, replacing any
discrepant bearings with stainless steel bearings, and conducting a
test to ensure that the NLG free-fall mechanism extends properly. This
proposal is prompted by a report indicating that, during an operational
test of the NLG, the landing gear failed to extend. The actions
specified by the proposed AD are intended to prevent the bearings from
seizing, which could lead to the loss of NLG free-fall extension
capability.
DATES: Comments must be received by May 12, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-215-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 Huber, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2589; 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-215-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-215-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 all Airbus Model A300, A300-600, and A310
series airplanes. The DGAC advises that one Model A300 operator
reported that, during an operational test of free-fall extension of the
nose landing gear (NLG), the free-fall handle could not be rotated and
the NLG failed to extend.
Investigations revealed that after 17,000 flight cycles and 27,000
flight hours, four bearings of the NLG free-fall mechanism were
severely corroded and had seized. The bearings are located in the
mechanical control linkage of the NLG free-fall mechanism. Analysis
disclosed that the corroded bearings were made of carbon steel instead
of stainless steel, as specified in the type design.
Corrosion of the bearings could cause them to seize, which, if not
corrected,
[[Page 15442]]
could lead to the loss of NLG free-fall extension capability.
Explanation of Relevant Service Information
Airbus has issued the following service bulletins, all dated April
29, 1996, which describe procedures for inspecting the four bearings
located in the mechanical control linkage of the NLG free-fall
mechanism for discrepancies, replacing carbon steel bearings with
stainless steel bearings, and conducting a test to ensure that the NLG
free-fall mechanism extends properly:
Service Bulletin A300-32-0418, Revision 1.
Service Bulletin A300-32-6061, Revision 1.
Service Bulletin A310-32-2098, Revision 1.
Accomplishment of these procedures will preclude potential
corrosion and seizure of the bearings, which could lead to the loss of
NLG free-fall extension capability.
The DGAC classified these service bulletins as mandatory and issued
French airworthiness directive (C/N) 96-052-197(B), dated March 13,
1996, in order to assure the continued airworthiness of these airplanes
in France.
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 require inspecting the four
bearings located in the mechanical control linkage of the NLG free-fall
mechanism for discrepancies, replacing discrepant bearings with
stainless steel bearings, and conducting a test to ensure that the NLG
free-fall mechanism extends properly. The actions would be required to
be accomplished in accordance with the service bulletins described
previously.
Cost Impact
The FAA estimates that 127 Model A300, A300-600, and A310 series
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 14 work hours per airplane to accomplish
the proposed actions, and that the average labor rate is $60 per work
hour. Required parts would cost approximately $552 per airplane. Based
on these figures, the cost impact of the proposed AD on U.S. operators
is estimated to be $176,784, or $1,392 per airplane.
The cost impact figure discussed above is 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-215-AD.
Applicability: All Model A300, A300-600, and A310 series
airplanes, 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 (d) 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 the bearings in the mechanical control linkage of the
nose landing gear (NLG) free-fall mechanism from seizing, which
could lead to the loss of NLG free-fall extension capability,
accomplish the following:
(a) Within 30 days after the effective date of this AD, conduct
an inspection to determine whether carbon steel or stainless steel
bearings are installed in the mechanical control linkage of the NLG
free-fall mechanism, in accordance with Airbus Service Bulletin
A300-32-0418 (for Model A300 series airplanes), A300-32-6061 (for
Model A300-600 series airplanes), or A310-32-2098 (for Model A310
series airplanes), all Revision 1, all dated April 29, 1996.
(b) If stainless steel bearings are installed, prior to further
flight, conduct a test to ensure that the NLG free-fall mechanism
extends properly, in accordance with Airbus Service Bulletin A300-
32-0418 (for Model A300 series airplanes), A300-32-6061 (for Model
A300-600 series airplanes), or A310-32-2098 (for Model A310 series
airplanes), all Revision 1, all dated April 29, 1996.
(c) If carbon steel bearings are installed, prior to further
flight, replace them with stainless steel bearings, and conduct a
test to ensure that the NLG free-fall mechanism extends properly, in
accordance with Airbus Service Bulletin A300-32-0418 (for Model A300
series airplanes), A300-32-6061 (for Model A300-600 series
airplanes), or A310-32-2098 (for Model A310 series airplanes), all
Revision 1, all dated April 29, 1996.
(d) An alternative method of compliance or adjustment of the
compliance time that
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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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(e) 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 26, 1997.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-8253 Filed 3-31-97; 8:45 am]
BILLING CODE 4910-13-U
