73-26-10 GENERAL DYNAMICS: Amdt. 39-1765. Applies to all Models 22, 22M, and 30A airplanes certificated in all categories incorporating Hamilton Standard Electric Freon Packs Part Numbers 574056 or 573970 (Model 22), P/N 573971 (Model 22M), P/N 574057 (Model 30A).
Compliance required as indicated.
To prevent partial or total loss of generator power due to electric freon pack compressor motor failure, accomplish the following:
(a) Model 22 airplanes.
Within 50 hours' time in service after the effective date of this AD, unless already accomplished, replace the freon pack fuses with LPN 110 fuses, per paragraph 2B., Accomplishment Instructions, General Dynamics Service Bulletin 880 S.B. No. 24-56, dated November 21, 1973, or later FAA-approved revisions. Airplanes with existing fuses rated at 110 amperes or less need not accomplish the foregoing installation.
(b) Models 22, 22M and 30A airplanes.
Within 300 hours' time in service after the effective dateof this AD, unless already accomplished, modify the freon pack compressor motor protectors, P/N 573667, per paragraph 2A., Accomplishment Instructions General Dynamics Service Bulletins 880 S.B. No. 24-56, dated November 21, 1973 (for Model 22), 880M S.B. No. 24-15, dated November 21, 1973 (for Model 22M), and 990 S.B. No. 24-16, dated November 21, 1973, (for Model 30A), or later FAA- approved revisions to the bulletins.
(c) Equivalent installations may be approved by the Chief, Aircraft Engineering Division, FAA Western Region, upon submission of adequate substantiating data.
(d) Airplanes may be operated to a maintenance base under special flight permits per Sections 21.197 and 21.199 of the Federal Aviation Regulations for the purpose of accomplishing this AD.
This amendment becomes effective February 1, 1974.