Posted by Lucian Drumond on Wednesday, September 29, 2004 at 10:52AM :
In Reply to: Runaway Cummins posted by David N. Lundstrom on Tuesday, September 28, 2004 at 10:36PM :
I also had an event with a A/c power generator. It was powered by 6 cylinder detroit 2 stroke diesel.They used these for ground maintenance on aircraft.I was outside working on some fight control problem and the avionics types were inside troubleshooting.
Those engines always varied there rpm, always hunting around.It started to accelerate we could tell it was not going to stop, we knew for sure when the generator kicked off and the aircraft power whent off. We went over and pulled the emergengy shut off. It;s a butterfly valve to shut air off and a mechanical fuel shut off. It was working until we heard a little pop"
That pop was the blower gasket imploding so the engine now had air.This engine also was bypassing some oil thru the rings,needed an overhaul. So now it had fuel,coupled with the fact it was a two stroke,short distance between powerstrokes. It accelerated again to the point that it exploded. We did run over after the first attempt to shut it down to make sure we had applied the shut off lever correctly,which we had.
Those facts were told to us after we picked up the pieces. I don't like two stroke detroit diesels they give me the heebe geeebees, specialy if they have alot of wear on them.