AD 91-26-06

91-26-06 AIRBUS INDUSTRIE: Amendment 39-8117. Docket 91-NM-243-AD.

Applicability: Model A320 series airplanes through manufacturer's serial number 109 on which Modification 21659 (specified in Airbus Industrie Service Bulletin A320-27-1012, Revision 2, dated September 23, 1991) has not been accomplished, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent reduced controllability of the airplane, due to freezing of relay 36 CE 3 in the energized state which, when coupled with an erroneous command from the SEC 2 computer could result in the disconnection of ELAC 1 and ELAC 2 computers and a runaway of the trimmable horizontal stabilizer (THS), accomplish the following:

(a) Install a new STP1 relay (P/N D0003002100100) having a date code newer than or equal to 88/41 A, in accordance with Airbus Industrie All Operator Telex 27-03, Revision 3, dated June 12, 1991, at the applicable time indicated in subparagraph (a)(1), (a)(2), or (a)(3) of this AD. (1) For airplanes that have accumulated more than 1,400 landings since retrofitted with SEC part number (P/N) B372ABM0606/B372BAM0404: Within 200 landings after the effective date of this AD. (2) For airplanes that have accumulated at least 800 landings but not more than 1,400 landings since retrofitted with SEC P/N B372ABM0606/ B372BAM0404: Prior to the accumulation of 1,600 total landings since retrofitted with SEC P/N B372ABM0606/B372BAM0404. (3) For airplanes that have accumulated less than 800 landings since retrofitted with SEC P/N B372ABM0606/B372BAM0404: Within 800 landings after the effective date of this AD.

(b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113. The request shall be forwarded through an FAA Principal Avionics Inspector, who may concur or comment and thensend it to the Manager, Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The installation required by this AD shall be done in accordance with Airbus Industrie All Operator Telex 27-03, dated June 12, 1991. 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, Airbus Support Division, Avenue Didier Daurat, 31700 Blagnac, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

(e) This amendment (39-8117, AD 91-26-06) becomes effective on January 3, 1992.