AD 92-01-04

92-01-04 MCDONNELL DOUGLAS: Amendment 39-8127. Docket No. 91-NM-237-AD.

Applicability: Model MD-11 series airplanes; equipped with McDonnell Douglas Electronic Systems Company Central Aural Warning System (CAWS), Part Number H05A0035-50 or Part Number H05A0035-51; certificated in any category.

Compliance: Required as indicated unless previously accomplished.

To eliminate the loss of Autopilot Disconnect, Windshear, Altitude, Stabilizer in Motion, Radio Altitude, and Overspeed aural alerts, accomplish the following:

(a) Within 5 days after the effective date of this AD, and thereafter prior to the first flight of each day, with the aircraft power active, accomplish the following:

(1) Position or verify that CAWS circuit breakers B1-1018, B1-1381, and B1-1019 are closed.

(2) Cycle all three CAWS circuit breakers to the open position. Leave the circuit breakers open for a minimum of five seconds.

(3) Return all three circuit breakers to the closed position.

(b) Within 60 days after the effective date of this AD, replace the CAWS unit in accordance with McDonnell Douglas Alert Service Bulletin A31-18, dated November 11, 1991. Such replacement constitutes terminating action for the requirements of paragraph (a) of this AD.

(c) 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Avionics Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.

(d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(e) The replacement requirement of this AD shall be done in accordance with McDonnell Douglas Alert Service Bulletin A31-18, dated November 11, 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California, 90846. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

(f) This amendment (39-8127, AD 92-01-04) becomes effective on January 24, 1992.