93-24-09 BRITISH AEROSPACE: Amendment 39-8758. Docket 93-NM-65-AD. Supersedes AD 92-01-01, Amendment 39-8124.
Applicability: Model ATP airplanes; serial numbers 2001 through 2053 inclusive; certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To prevent the loss of all primary electric power sources, accomplish the following:
(a) Within 30 hours time-in-service after January 24, 1992, (the effective date of AD 92-01-01, Amendment 39-8124), accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD:
(1) Trip and lock out the alternative three-phase circuit breaker to each transformer rectifier unit (TRU), and perform an operational test to ensure that the auto-changeover system is inoperative, in accordance with British Aerospace Service Bulletin ATP-24-42-10244A, Revision 1, dated November 7, 1991.
(2) Revise the Emergency Procedures and Abnormal Procedures Sections of the FAA-approved Airplane Flight Manual (AFM) to include AFM (Document No. ATP 004) Temporary Revision No. 22 (T/22), Issue 1, dated November 1, 1991.
(3) Amend the AFM, Section 0.25.0, in accordance with paragraph 2.(6) of British Aerospace Service Bulletin ATP-24-42-10244A, Revision 1, dated November 7, 1991.
(b) Within 6 months after the effective date of this AD, accomplish paragraphs (b)(1) and (b)(2) of this AD.
(1) Replace the currently-installed Cutler Hammer contactor type SM15-CK-A6 or SM15-CK-A8 with Leach contactor type HA1F, in accordance with British Aerospace Service Bulletin ATP-24-49-10247A, Revision 1, dated October 23, 1992.
(2) Revise the Emergency Procedures and Abnormal Procedures Sections of the AFM (Document No. ATP-004) to include Temporary Revision No. T/26, Issue 1, dated May 22, 1992.
(c) Accomplishment of the contactor replacement and the AFM revision required by paragraph (b) of this AD constitutes terminating action for the requirements of paragraph (a) of this AD. The AFM revisions required by paragraphs (a)(2) and (a)(3) of this AD are revised as necessary by incorporation of AFM Temporary Revision No. T/26, Issue 1, dated May 22, 1992, and the automatic alternative three-phase power supply to each TRU is re-activated.
(d) 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.
(e) 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.
(f) The actions shall be done in accordance with British Aerospace Service Bulletin ATP-24-42-10244A, Revision 1, dated November 7, 1991; British Aerospace Service Bulletin ATP-24-49-10247A, Revision 1, dated October 23, 1992; Temporary Revision No. 22 (T/22), Issue 1, dated November 1, 1991; and Temporary Revision No. T/26, Issue 1, dated May 22, 1992. Revision 1 of British Aerospace Service Bulletin ATP-24-49-10247A contains the following list of effective pages:
Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 3-34, 39,
81-84
1
October 23, 1992
2, 35-37, 41,
43, 45, 47,
49, 51, 53, 55,
57, 59, 61, 63,
65, 67, 69, 71,
73, 75, 77, 79
Original
July 15, 1992
38, 40, 42, 44,
46, 48, 50, 52,
54, 56, 58, 60,
62, 64, 66, 68,
70, 72, 74, 76,
78, 80
(These pages are not used)
The incorporation by reference of British Aerospace Service Bulletin ATP-24-42-10244A, Revision 1, dated November 7, 1991, and Temporary Revision No. 22 (T/22), Issue 1, dated November 1, 1991, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of January 24, 1992 (57 FR 784, January 9, 1992). The incorporation by reference of the remainder of the service documents listed above is 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 Jetstream Aircraft, Inc., Librarian for Service Bulletins, P.O. Box 16029, Dulles International Airport, Washington, DC. 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.
(g) This amendment becomes effective on January 21, 1994.