55-08-04 PIPER: Applies to Model PA-22 Serial Numbers 22-1621 Through 22-1625, 22-1627, 22-1630, 22-1633, 22-1634, 22-1637.
Compliance required as soon as possible but not later than July 1, 1955.
The Hypass No. 48P6 ignition filters should be removed from the magnetos and replaced with magneto filter, Piper No. 63149 (Lear) obtainable from the Piper Service Department. It has been found that the Hypass No. 48P6 filters short and ground out the magnetos when subjected to a temperature which has been reported to be equal to the engine accessory temperature after a series of takeoffs have been performed.