[Federal Register Volume 59, Number 218 (Monday, November 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-27968]


[[Page Unknown]]

[Federal Register: November 14, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-141-AD]

 

Airworthiness Directives; Airbus Model A320 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 Model A320 series 
airplanes. This proposal would require replacement of the check valves 
of the thrust reverser with modified valves on certain airplane 
configurations and the replacement of the manual control valves of the 
thrust reverser with modified valves on certain other airplane 
configurations. This proposal is prompted by recent engineering 
analysis, which revealed that if the non-return valve installed on the 
hydraulic return line of the thrust reverser were to jam in the closed 
position, it could cause pressurization of the Hydraulic Control Unit 
(HCU). The actions specified by the proposed AD are intended to prevent 
possible pressurization of the HCU, due to jamming of the non-return 
valve in the hydraulic return line, and consequent deployment of a 
thrust reverser during flight, which could affect the controllability 
of the airplane.

DATES: Comments must be received by December 27, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-141-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: Stephen Slotte, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 227-1320.

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 94-NM-141-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. 94-NM-141-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 certain Airbus A320 series airplanes. The 
DGAC advises that recent engineering analysis has revealed that, if the 
non-return valve installed on the thrust reverser hydraulic return line 
on a Model A320 series airplane were to jam in the closed position for 
any reason, it could cause pressurization of the Hydraulic Control Unit 
(HCU). Pressurization of the HCU, if not corrected, could result in the 
deployment of a thrust reverser during flight, which could affect the 
controllability of the airplane. (There have been no incidents of the 
non-return valve jamming on in-service airplanes, however.) -
    Airbus has issued Service Bulletin A320-29-1048, Revision 1, dated 
December 4, 1992, which describes procedures for replacing the Engine 1 
and Engine 2 thrust reverser check valves with modified valves on 
airplanes equipped with CFM series engines, and replacing the Engine 1 
and Engine 2 thrust reverser manual control valves with modified valves 
on airplanes equipped with International Aero Engines (IAE) engines. 
Replacement in accordance with the service bulletin of these valves 
with a modified check or manual control valve on the thrust reverser 
line will allow for leakage and prevent pressurization of the HCU. The 
DGAC has classified this service bulletin as mandatory and issued 
French Airworthiness Directive 94-059-054(B), dated March 16, 1994, in 
order to assure the continued airworthiness of these airplanes in 
France. -
    This airplane model is manufactured in France and is 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. -
    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 replacing the 
thrust reverser check valves with modified valves on Engine 1 and 
Engine 2 of airplanes equipped with CFM series engines. It would also 
require replacing the thrust reverser manual control valves with 
modified valves on the Engine 1 and Engine 2 of airplanes equipped with 
IAE engines. The actions would be required to be accomplished in 
accordance with the service bulletin described previously. -
    The FAA estimates that 53 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 3 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $9,540, or $180 per airplane. -
    The total 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.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended] -

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Airbus Industrie: Docket 94-NM-141-AD.

    -Applicability: Model A320 series airplanes as specified in 
Airbus Industrie Service Bulletin A320-29-1048, Revision 1, dated 
December 4, 1992, certificated in any category. -
    Compliance: Required as indicated, unless accomplished 
previously. -
    To prevent deployment of a thrust reverser during flight, and 
consequently affecting the controllability of the airplane, 
accomplish the following: -
    (a) Within 5 months after the effective date of the AD, 
accomplish paragraph (a)(1) or (a)(2) of this AD, as applicable, in 
accordance with Airbus Industrie Service Bulletin A320-29-1048, 
Revision 1, dated December 4, 1992. -
    (1) For airplanes equipped with CFM series engines: Replace the 
Engine 1 and Engine 2 check valves of the thrust reverser in the 
nacelle with modified valves as specified in the service bulletin. -
    (2) For airplanes equipped with International Aero Engines 
(IAE): Replace the Engine 1 and Engine 2 manual control valves of 
the thrust reverser on the pylon with modified valves as specified 
in the service bullein. -
    (b) 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.

    -Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    -(c) 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 November 7, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-27968 Filed 11-10-94; 8:45 am]
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