To: Brian Abraham
I was interested to read on the thread 'Bell misleads 407 owners' Lu Zuckerman's account of the 205 incident where the engine oversped the rotor and Bell claimed the clutch had been damaged by compressor stalls.
Actually, the Bell rep covered up the fact that the engine had experienced three compressor stalls. I found out about it when we pulled the unit out of the transmission. The rollers and the cams were destroyed. It was not until the accident report had been submitted and Bell signed off on pilot error that the Bell rep came forward and told me about the three compressor stalls.
What made matters worse there was no mention about the three compressor stalls in the maintenance records and the normal protocols initiated after a compressor stall had not been implemented.
Many years ago the US Army took delivery of a brand new H-34. They were checking out a pilot who had never flown in a helicopter with a fuel priming system. On helicopters that this pilot had flown the twist grip was rotated to pump fuel through the carburetor. The pilot was twisting the throttle but on this helicopter the throttle canceller had been misrigged and it allowed the helicopter to start with the throttle in the open position. The pilot cranked the engine and it caught on the first two turns and with the throttle wide open the engine spun up to 2800 RPM. This caused the blocker plate in the hydromechanical clutch to overstress to the point that it failed and the engine engaged into the rotor system at 2800 RPM. The helicopter, which had only about 16 hours on it, was written off and turned over to the training school to be used as a training aid.
