60-10-08 PIPER: Amdt. 149 Part 507 Federal Register May 13, 1960. Applies to All PA- 22, PA-20, PA-18 Airplanes Equipped With Two Wing Tanks.
Compliance required prior to July 15, 1960, and every 100 hours' time in service thereafter.
Several accidents have occurred involving engine fuel starvation attributed to a lack of detent action in the fuel selector valve (P/N 11383), causing the pilot to position the selector improperly.
If the detent pin in the valve shaft is improperly centered or if the spring retaining washer is installed upside down, the pin will not engage the slotted detent washer. Therefore, the fuel selector valve in the above listed models must be thoroughly cycled to determine whether or not detent engagement is positive. There should be four distinct detents in one complete cycle. If detent engagement is not positive, the valve must be replaced prior to further flight.
Also, determine if the position of the fuel valve handle at detent engagement coincides with the proper markings on the indicator plate. If the handle does not coincide with the markings, the plate must be repositioned accordingly.
(Piper Service Bulletin No. 141 covers this subject.)