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鈥檚 type rating instructor qualification. The engine failure was simulated by the commander reducing Engine No聽1鈥檚 throttle to idle. Shortly afterwards the commander increased the throttle setting, but Engine聽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鈥檚 skid assembly was deformed as a result of the landing, the touchdown forces did not exceed the manufacturer鈥檚 threshold for it to be classified as a 鈥榟ard landing.鈥� 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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