AAIB investigation to MBB-BK 117 C-2, G-MPSB
Firm landing following a simulated engine failure on takeoff, North Weald Airfield, Essex, 12 March 2021.
Summary:
This serious incident occurred during the demonstration of an engine failure after takeoff emergency procedure on a revalidation flight for the commander’s type rating instructor qualification. The engine failure was simulated by the commander reducing Engine No 1’s throttle to idle. Shortly afterwards the commander increased the throttle setting, but Engine No 1 did not respond. During attempts to resolve the problem, the throttle setting for Engine No 2 was inadvertently reduced, resulting in insufficient power being available for continued safe flight. The commander rejected the takeoff and executed a firm landing within the airfield boundary.
While the aircraft’s skid assembly was deformed as a result of the landing, the touchdown forces did not exceed the manufacturer’s threshold for it to be classified as a ‘hard landing.’ The subsequent engineering investigation did not find any evidence of malfunction in the engine control systems. Engine No 1 probably did not respond because the rotor rpm droop compensation had been inadvertently trimmed in the wrong direction.
Bulletin Addendum
This addendum is published to make Safety Recommendations in areas where the helicopter manufacturer had previously stated it intended to take safety action.
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