This mechanic describes how some Cessna starter contactors (P/N S2443-2) have failed to “release” after engine start. Although this aircraft is equipped with a “starter engaged” warning light, it was not detectable after initial engine start, possibly related to low engine RPM having little alternator output to the bus. Continuous contactor connection destroys both the contactor and the starter.

“Continental has begun supplying a compact, lightweight starter (P/N 655566F24V by Iskra) on new engines,” states the mechanic. “This aircraft had a factory new engine installed 42 hours prior to this event. It would be the first lightweight starter installed on this aircraft. Our investigation indicates the lightweight starters have a higher current draw than the larger starter used previously. We suspect the Cessna contactor cannot handle the load. For the present we will probably replace the starter contactors at each engine change to see if that will help avoid this problem.”

(The submitter includes two additional reports describing the same stuck-starter occurrences on the same type aircraft having the same part numbers. These will be included in the SDR data base.)

Part total time: 7616 hours.