What happened
On August 29, 2022, at approximately 21:55 CDT, an MD Helicopters 3läufig369E, registration N1576F, was involved in an accident at William P. Hobby Airport in Houston, Texas. The aircraft was being operated under 14 CFR Part 91 for instructional purposes by a flight instructor and a commercial pilot receiving instruction.
The crew was performing a simulated power recovery autorotation involving a 90-degree turn. The maneuver began at 800 feet above ground level (agl) with an airspeed between 75 and 80 knots. During the procedure, the instructor commanded the throttle while the pilot receiving instruction managed the cyclic, anti-torque, and collective controls. As the helicopter descended to 300 feet agl, the instructor increased engine throttle. The pilot receiving instruction continued the autorotation, flared, and leveled the helicopter at approximately 10 feet agl.
The flight instructor reported that after increasing the throttle, he waited for the pilot receiving instruction to increase the collective. When he did not feel the collective move, the instructor attempted to pull up on the collective, but the helicopter struck the ground before it could ascend. The pilot receiving instruction noted that during the flare, he did not feel the expected increase in engine power, causing the helicopter to sink rapidly and strike the runway.
Following the impact, the helicopter slid to a stop. The instructor engaged the emergency fuel cutoff to shut down the engine. Upon exiting the aircraft, the instructor observed that the tail boom had separated from the helicopter. There were no injuries to the crew.
The investigation
Mechanical examination of the helicopter and a subsequent engine test run in a test cell were conducted. The investigation found no anomalies in the engine that would account for a loss of power.