AD 70-15-09

70-15-09 BRITISH AIRCRAFT CORPORATION: Amdt. 39-1038. Applies to Model BAC 1-11 200 and 400 series airplanes.

Compliance is required as indicated.

(a) Within the next 750 hours' time in service after the effective date of this AD, unless already accomplished, replace the existing 200 ampere fuse in the APU starter motor circuit with a 150 ampere fuse in accordance with British Aircraft Corporation Model BAC 1-11 Service Bulletin No. 49-PM4480 dated November 10, 1969, or later ARB-approved issue, or an FAA-approved equivalent.

(b) For airplanes which have not incorporated BAC 1-11 Modification PM2518 on or before the effective date of this AD, within the next 750 hours' time in service after the effective date of this AD, unless already accomplished, modify the APU starting system as follows:

(1) Incorporate a second power relay in accordance with British Aircraft Corporation Model BAC 1-11 Service Bulletin No. 49-PM2429, Revision 4, dated June 1, 1967, or later ARB-approved issue, or an FAA- approved equivalent.

(2) Incorporate a separate APU start control in accordance with British Aircraft Corporation Model BAC 1-11 Service Bulletin No. 49-PM2891, Revision 5 dated December 15, 1969, or later ARB-approved issue, or an FAA-approved equivalent.

(c) For airplanes which have incorporated BAC 1-11 Modification PM2518 on or before the effective date of this AD, within the next 1500 hours' time in service after the effective date of this AD unless already accomplished, modify the APU starting system in accordance with paragraphs (b)(1) and (b)(2) of this AD. (British Aircraft Corporation Model BAC 1-11 Alert Service Bulletin No. 49-A-PM4480 covers this subject.)

This amendment becomes effective August 16, 1970.