67-29-03 FAIRCHILD-HILLER: Amdt. 39-499 Part 39 Federal Register October 25, 1967. Applies to all F-27J and FH-227 aircraft with installed Solar Auxiliary Power Unit Model T-62T-25, Serial Nos. S-408000 to S-408099 inclusive.
Compliance required as indicated unless already accomplished, or unless APU is rendered electrically inoperative and APU controls are placarded to prohibit operation.
To provide adequate APU fire detection system reliability and sensitivity, accomplish the following modifications:
(a) Within the next 100 operational APU hours following the effective date of this AD, install an additional fire detector, Solar P/N 7447-2, (set at 400 25 degrees F) in accordance with Fairchild-Hiller Service Bulletin Nos. F-27-49-4 Revision 3, dated Sept. 25, 1967 or FH-227-49-4 Revision 3 dated Sept. 25, 1967 as applicable, or later FAA approved revision, or an equivalent modification approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
(b) Within the next 100 operational APU hours following the effective date of this AD, install MIL-W-25038B fire resistant wire in the fire detection circuit in accordance with Fairchild-Hiller Service Bulletin Nos. F27-49-6 dated July 10, 1967 or FH227-49-6 dated July 10, 1967 as applicable, or later FAA-approved revision, or an equivalent modification approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
(c) Within the next 200 operational APU hours following the effective date of this AD, replace the two existing 700 degree fire detectors, Solar P/N 7447-1 with two 400 + 25 degree F Fire detectors Solar P/N 7447-2.
NOTE. - Compliance with paragraph (c) may be accomplished by arranging for the detector manufacturer, Fenwal, Inc. of 900 Main Street, Ashland, Massachusetts 01721, Solar P/N 7447-1 with two 400+25 degree F fire and reidentify the detector by P/N 7447-2.
(d) Upon the effective date of this AD, APU operational hours will belogged until such time as the entire AD has been complied with.
This amendment effective October 27, 1967.