92-11-04 BRITISH AEROSPACE: Amendment 39-8254. Docket No. 91-NM-166-AD.
Applicability: British Aerospace Model ATP airplanes; as listed in British Aerospace Service Bulletin ATP-24-34, dated April 25, 1991, and British Aerospace Service Bulletin ATP-33-8, Revision 2, dated April 11, 1991; certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To prevent inaccurate navigation when using the standby compass, accomplish the following:
(a) Within 14 days after the effective date of this AD, fabricate and install a temporary placard near the standby magnetic compass, worded as follows:
"WARNING: OPERATION OF CABIN ROOF AND SIDEWALL LIGHTING, PITOT HEAT, AND STALL WARNING SYSTEMS MAY INDUCE EXCESSIVE ERROR IN THE MAGNETIC COMPASS READINGS."
(b) Within 8 months after the effective date of this AD, accomplish the following:
(1) Modify the earthing arrangements to the pitot static and stall warning systems (Modification 10194A) and to the overhead stowage units (Modification 10194B), as applicable, in accordance with British Aerospace Service Bulletin ATP 24-34, dated April 25, 1991.
(2) Modify the roof and sidewall light wiring (Modification 35113A) in accordance with British Aerospace Service Bulletin ATP-33-8, Revision 2, dated April 11, 1991.
(3) Accomplish a compass swing of the standby compass in accordance with British Aerospace Service Bulletin ATP-24-34, dated April 25, 1991.
(4) Remove the temporary placard installed in accordance with 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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.(d) 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.
(e) The modifications shall be done in accordance with British Aerospace Service Bulletin ATP-24-34, dated April 25, 1991; and British Aerospace Service Bulletin ATP-33-8, Revision 2, dated April 11, 1991. These service bulletins contain the following list of effective pages:
Service Bulletin No.
Page Number
Revision Level
Date
ATP-24-34
1-3, 5-21,
Original
April 25, 1991
23, 25, 27,
29, 31, 33,
35, 37, 39,
41, 43, 45,
47, 49, 51,
53-54
4, 22, 24,
(These pages are not used)
26, 28, 30,
32, 34, 36,
38, 40, 42,
44, 46, 48,
50, 52
ATP-33-8
1
2
April 11, 1991
Revision 2
2-5, 19-20,
1
September 5, 1990
31, 33
6-18, 21, 23,
Original
April 29, 1990
25, 27,29,
35, 37, 39-40
22, 24, 26,
(These pages are not used)
28, 30, 32,
34, 36, 38
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 British Aerospace, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC.
(f) This amendment becomes effective on July 23, 1992.