AD 95-24-08

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires replacement of the check valves of the thrust reverser with modified valves on certain airplanes and the replacement of the manual control valves of the thrust reverser with modified valves on certain other airplanes. This amendment 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 this AD are intended to prevent such 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; this condition, if not corrected, could adversely affect the controllability of the airplane.

Final rule.

95-24-08 AIRBUS: Amendment 39-9440. Docket 94-NM-141-AD.

Applicability: Model A320 series airplanes; as listed in Airbus Industrie Service Bulletin A320-29-1048, Revision 1, dated December 4, 1992, and Revision 2, dated September 1, 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 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 use the authority provided in paragraph (b) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of thechanged configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent deployment of a thrust reverser during flight, which could adversely affect the controllability of the airplane, accomplish the following:

(a) Within 5 months after the effective date of the AD, accomplish the requirements of 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, or Revision 2, dated September 1, 1994.
(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 1and Engine 2 manual control valves of the thrust reverser on the pylon with modified valves as specified in the service bulletin.

(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 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.

(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.

(d) The replacements shall be done in accordance with the following Airbus service bulletins, which contain the specified list of effective pages:

Service Bulletin
Number and Date

Page Number
Revision Level
Shown on Page
Date
Shown on Page
A320-29-1048
Revision 2
September 1, 1994
1-5
7-8, 11
6, 9-10, 12-15
2
1
Original
September 1, 1994
December 4, 1992
April 7, 1992
A320-29-1048
Revision 1
December 4, 1992
1-3, 5, 7-8, 11
4, 6, 9-10, 12-15
1
Original
December 4, 1992
April 7, 1992

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on December 27, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Airbus Model A320 series airplanes was published in the Federal Register on November 14, 1994 (59 FR 56433). That action proposed to require replacing the thrust reverser check valves with modified valves on Engine 1 and Engine 2 of airplanes equipped with CFM series engines. It also proposed to require replacing the thrust reverser manual control valves with modified valves on the Engine 1 and Engine 2 of airplanes equipped with International Aero Engines (IAE) engines.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the two comments received.

Both commenters support the proposal.

Just prior to the publication of the proposal, Airbus issued Service Bulletin A320-29-1048, Revision 2, dated September 1,1994. This revision is essentially identical to Revision 1, which was cited in the proposal as the appropriate source of service information; it differs only in the listing of the current operators of affected airplanes. The FAA has revised the final rule to include Revision 2 of the service bulletin as an additional source of service information.

Additionally, as a result of communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been added to this final rule to clarify this long-standing requirement.

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 53 airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $9,540, or $180 per airplane. Thiscost impact figure is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."
List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 USC 106(g), 40101, 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: