64-01-01 AIRBORNE MECHANISMS: Amdt. 666 Part 507 Federal Register January 3, 1964. Applies to All Aircraft Using Vacuum Pumps Models 113A5 and 113A8, Serial Numbers 7G2494 through 7G2678, 8G2679 through 8G2892, 9G2893 through 9G3250 and 10G3251 through 10G3714, and All Vacuum Pumps Models 113A1, 113A2, 113A5 and 113A8 in Which the Splined Drive Coupling, Airborne Mechanisms P/N B1001A2, Has Been Replaced After July 22, 1963.
Compliance required within 10 hours' time in service after the effective date of this AD.
In order to remove defective splined drive couplings which render the vacuum flight instruments inoperative accomplish the following:
(a) On Piper aircraft, unless already accomplished, replace all the vacuum pump splined couplings identified in Piper Service Bulletin No. 218, in accordance with that service bulletin before further flight.
(b) On other aircraft, inspect all Airborne Mechanisms P/N B1001A2 couplings for a bright yellow band on the shoulder of the coupling. (The band is visible through the openings in the pump base.) Replace couplings which do not have a yellow band with a coupling having the yellow band before further flight.
(Airborne Mechanisms Service Letter No. 5 dated November 5, 1963, and Piper Service Bulletin No. 218 dated November 11, 1963, pertain to this same subject.)
This directive effective January 9, 1964.