66-13-05 VERTOL: Amdt. 39-240 Part 39 Federal Register May 19, 1966. Applies to Model 107-II Helicopters.
Compliance required within the next 130 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent further simultaneous engine false fire warnings caused by electrical wiring system malfunction:
(a) Accomplish the following or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region
(1) Isolate each fire detector system test circuit by replacing wafer test switch, P/N 1-1917- 1N5, with switch, P/N 1-1919-2N5; and
(2) Revise the wiring arrangement in accordance with Vertol Service Bulletins Nos. 107-219 and 107-219A dated September 20, and October 22, 1965, respectively, or later FAA-approved revisions.
(b) After modification in accordance with (a), functionally test the engine fire detection system as described in Vertol 107-2 Maintenance Manual, Chapter 16.
Thisdirective effective June 18, 1966.