An investigation determined that the crash resulted from failure of the plane's propeller control unit, which caused the pilots to lose control of the aircraft.
12.
The major problems of the T40 were its fragile gearbox, and the propeller control system which used 25 vacuum tubes, and was far from reliable.
13.
Agency records showed that in December 1993, the right propeller control unit of the the plane that crashed Monday was found to be defective and was replaced.
14.
This membrane is cheaper to operate than the Propeller Control System + and the Nozzle System but is not as effective as the PCS + in reducing cavitation.
15.
FAA records show that in December 1993, the right propeller control unit of the the plane that crashed on Monday was found to be defective and was replaced.
16.
Of the sixteen examples built, the twelve used for evaluation suffered similar problems to the R3Y . Propeller control problems and gearbox failures were among the more common problems.
17.
Also Monday, records released by the FAA Monday showed that the 1997 annual inspection of the plane that Kennedy bought last April uncovered a problem with its propeller control.
18.
The engineers were intended to monitor engine synchronisation and allow the pilot to fly without worrying about engine status, although the pilot could override the engineers'decisions on engine and propeller control.
19.
Actual flight tests of the aircraft revealed several problems : The contra-rotating props caused constant heavy drive-shaft vibration and the government-supplied gearboxes had frequent malfunctions and reduced the effectiveness of propeller control.
20.
The tension of the speeder spring is set by the propeller control lever, which sets the RPMs . The governor will maintain that RPM setting until an engine overspeed or underspeed condition exists.
