AD 67-23-04

67-23-04 FAIRCHILD-HILLER: Amdt. 39-458, Part 39, Federal Register August 5, 1967. Applies to Model F-27J Airplanes, Serial Numbers 111, and 113 through 121, inclusive and FH-227 Series Airplanes, Serial Numbers 501 through 520, inclusive. Incorporating Solar Auxiliary Power Unit, Model T62T25.

Compliance required within the next 400 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent electrical damage to the A.C. engine-driven generator resulting from an unregulated and unloaded condition when the APU-driven generator (A.C.) is switched on the line, accomplish the following:

(a) Rewire the engine-driven A.C. generator control sensing circuit in accordance with Fairchild-Hiller F-27 Service Bulletin 30-12, Revision No. 1, dated September 15, 1966, for F-27J aircraft and Fairchild-Hiller FH-227 Service Bulletin 30-1 dated August 23, 1966, for FH-227 aircraft, or later revision approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, or perform an equivalent rewiring modification, approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

(b) Upon request, with substantiating data submitted through an FAA maintenance inspector, an increase in the compliance time may be approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

This amendment effective August 31, 1967.