AD 67-29-02

67-29-02 FAIRCHILD-HILLER: Amdt. 39-498 Part 39 Federal Register October 25, 1967. Applies to Type F-27 and FH-227 Airplanes.

Unless already accomplished, compliance is required with the next 200 hours' time in service after the effective date of this AD. To compensate for the loss of electrical power to the copilots' flight and navigation instruments (attitude, turn and bank, and gyroscopic direction indicators), in the event of a single ground fault in the D.C. power system, accomplish the following:

(a) In aircraft where the emergency electrical power to operate the copilot attitude indicator, turn and bank indicator, and gyroscopic direction indicator is derived from the D.C. power system, modify the emergency electrical power system for these instruments in a manner such that the emergency electrical power is derived from the right engine driven emergency alternator. Accomplish this by loading the emergency alternator (increasing the power factor to unity) to allowit to adequately power the three (3) instrument systems. The modifications must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(b) Modifications accomplished in accordance with Fairchild-Hiller FH-227 Service Bulletin 24-1, dated April 25, 1967, or Fairchild-Hiller FH-227 Service Bulletin 24-2, dated May 22, 1967, for the serial number applicable in the Bulletins, or later FAA-approved revisions, are acceptable for showing compliance with this Airworthiness Directive.

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

This amendment effective October 27, 1967.