# Airworthiness Directives; Airbus Model A320 Series Airplanes > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A94-27968 ## Record - **Collection:** Federal Register - **Document type:** Uncategorized Document - **Published:** November 14, 1994 ## Text 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). ----------------------------------------------------------------------- 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] BILLING CODE 4910-13-U --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-27968. Public record. Not legal advice.