64-21-05 PIPER: Amdt. 809 Part 507 Federal Register September 15, 1964. Applies to Model PA-30 Aircraft Equipped With the Hartzell HC-E2YL-2B/7663-4 Propeller and Model PA-23-250 Aircraft Equipped With the Hartzell HC-E2YK-2RB/8465-7R Propeller.
Compliance required as indicated.
There have been several instances of propeller failure on the Piper PA-30 aircraft. The replacement of governor relief valve springs in accordance with Hartzell Service Bulletin No. 88 dated July 2, 1964, as amended July 8, 1964, has not eliminated these failures. The propeller installation on Piper Model PA-23-250 is similar in design and operation to that used on the Model PA-30. Accordingly, this AD is being made applicable to both Models PA-30 and PA-23-250. To preclude further failures, comply with the following:
(a) For aircraft having propellers previously serviced in accordance with Hartzell Service Bulletin No. 88 dated July 2, 1964, as amended July 8, 1964, service the propeller governors in accordance with Hartzell Service Bulletin No. 88A dated August 4, 1964, within 10 hours' time in service after the effective date of this AD.
(b) For aircraft having propellers which have not been previously serviced in accordance with Hartzell Service Bulletin No. 88A dated July 2, 1964, as amended July 8, 1964, service the propellers in accordance with these service bulletins and, in addition, in accordance with Hartzell Service Bulletin No. 88A dated August 4, 1964, within 10 hours' time in service after the effective date of this AD.
This supersedes AD 64-16-08.
This directive effective September 16, 1964.