To: 212 Man
The incident you referenced was not the result of a quality problem. Here is the story and it fits right into the question raised by Vfrpilotpb regarding being the last person to fly the aircraft after a previous pilot screwed it up.
It was an Agusta-Bell 205 that was being piloted by An American pilot working for Bristow. Bristow had a contract with the Iranian Air Force to train their pilots. The American had an Iranian student and was teaching him to autorotate. The pilot chopped the power and told the Iranian student to take over. I won’t go into what the student did but he was very slow in taking over the controls. Rotor speed was bleeding off at a rapid rate so the pilot put the 205 into a dive to build up airspeed and rotor speed. At the same time, he tried to reengage the engine but it was as if there were no freewheeling unit installed. He tried several times and the engine needle oversped the rotor needle. The pilot elected to make a run-on engine out landing. The ground was very soft and undulating and offered no resistance to the skids. When the helicopter came to a stop the pilot who had already notified the base was filling out his flight report as the rotor speed bled down. He heard a loud crack and the helicopter lurched to the right accompanied by a loud bang. The rotor hit the pylon.
Immediately thereafter, there was another even louder bang and the stabilizer bar came crashing through the fuselage just behind the student.
There was a lot of infighting on the part of Bell in trying to say that the pilot had pulled his cyclic so far back that he hit the pylon. This is a physical impossibility unless the transmission support structure and primary airframe structure had been compromised. This was later proven false as the trannie was pulled out and put back in several times proving that the structure had not been deformed.
To make a long story a tad shorter when the trannie was disassembled the freewheeling unit was shown to be totally destroyed. The only thing that could cause this sort of damage was a compressor stall. The records were checked and there was no write-up of a compressor stall. If the helicopter had been subjected to a compressor stall the entire dynamic system and the driveline and engine had to be removed and checked for overstress. The airframe would also have to be checked.
The American pilot left the country to return to Bristow and the whole thing was swept under the carpet. Bell stuck with their story about pilot involvement.
Two weeks later a Bell techrep told the accident investigator that he was aware that the 205 had suffered at least two compressor stalls. He was a Bell techrep and he never reported it and just left it to chance. If the mast separation had taken place while in flight the helicopter would have crashed and the pilot would have been blamed for getting into a mast-bumping situation. The name of the accident investigator was Lu Zuckerman.
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The Cat
[This message has been edited by Lu Zuckerman (edited 04 April 2001).]