[Federal Register Volume 64, Number 123 (Monday, June 28, 1999)]
[Proposed Rules]
[Pages 34579-34581]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16334]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-106-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A319, A320, and A321
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 A319, A320, and
A321 series airplanes. This proposal would require modification of the
electro-distributor for the nose wheel steering servo-control. 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 uncommanded nose
landing gear wheel rotation, due to defective seals in the wheel
steering selector valve of the hydraulic control unit for the nose
landing gear, which could result in reduced controllability of the
airplane.
DATES: Comments must be received by July 28, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-106-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 99-NM-106-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. 99-NM-106-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Direction Gorale 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 A319, A320, and A321 series
airplanes. The DGAC advises that there have been several cases of
uncommanded nose landing gear wheel rotation on in-service airplanes.
Such uncommanded rotation was caused by defective seals in the wheel
steering selector valve of the hydraulic control unit for the nose
landing gear, which resulted in failure of the nose landing gear wheel
steering system. The seals
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were found to be extruded due to aging or the absence of a backup ring.
Uncommanded nose landing gear wheel rotation, if not corrected, could
result in reduced controllability of the airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A320-32-1197, Revision 01, dated
February 11, 1999, which describes procedures for modification of the
electro-distributor for the nose wheel steering servo-control. The
modification involves replacing the O-ring seals fitted to the electro-
distributor with new ``GREENE TWEED'' seals with a back-up ring.
Accomplishment of the action specified in the service bulletin is
intended to adequately address the identified unsafe condition. The
DGAC classified this service bulletin as mandatory and issued French
airworthiness directive 1999-124-129(B), dated March 24, 1999, in order
to assure the continued airworthiness of these airplanes in France.
Airbus Service Bulletin A320-32-1197 references MESSIER-BUGATTI
Service Bulletin C24736-32-3166, dated December 4, 1998, as an
additional source of service information for accomplishment of the
modification.
FAA's Conclusions
These airplane models are manufactured in France and are 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 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 action specified in the service bulletin described previously.
Cost Impact
The FAA estimates that 208 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 7 work
hours per airplane to accomplish the proposed modification, and that
the average labor rate is $60 per work hour. Required parts would cost
approximately $335 per airplane. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be
$157,040, or $755 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 99-NM-106-AD.
Applicability: Model A319, A320, and A321 series airplanes;
except those airplanes on which Airbus Modification 23740 was
accomplished during production, and those airplanes on which Airbus
Service Bulletin A320-32-1197, dated October 9, 1998, or Revision
01, dated February 11, 1999, has been accomplished; 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 (c) 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 uncommanded nose landing gear wheel rotation, due to
defective seals in the wheel steering selector valve of the
hydraulic control unit for the nose landing gear, which could result
in reduced controllability of the airplane, accomplish the
following:
Modification
(a) Within 12 months after the effective date of this AD, modify
the electro-distributor for the nose wheel steering servo-control in
accordance with Airbus Industrie Service Bulletin A320-32-1197,
Revision 01, dated February 11, 1999.
Note 2: Airbus Service Bulletin A320-32-1197 references MESSIER-
BUGATTI Service Bulletin C24736-32-3166, dated December 4, 1998, as
an additional source of service information for accomplishment of
the modification.
Note 3: Replacement of the by-pass valve in accordance with
MESSIER-BUGATTI Service Bulletin C24736-32-3126, dated February 15,
1995, as revised by Change Notice Number 1, dated March 16, 1999, is
considered acceptable for compliance with the action specified in
paragraph (a) of this AD.
Spares
(b) As of the effective date of this AD, no person shall install
a hydraulic control unit, part number C24736000 or C24736001, on any
airplane, unless it has been modified in accordance with the actions
required by paragraph (a) of this AD.
Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the
compliance time that
[[Page 34581]]
provides an acceptable level of safety may be used if approved by
the Manager, International Branch, ANM-116, 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, International Branch, ANM-
116.
Note 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(d) Special flight permits may be issued in accordance with
Sec. Sec. 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 5: The subject of this AD is addressed in French
airworthiness directive 1999-124-129(B), dated March 24, 1999.
Issued in Renton, Washington, on June 22, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-16334 Filed 6-25-99; 8:45 am]
BILLING CODE 4910-13-U
