Robinson R44 N611TH accident near Salinas, California

Probable cause

The partial loss of engine power after takeoff due to faulty wiring to the engine governor.

NTSB analysis

Shortly after takeoff, as the pilot turned the helicopter onto the crosswind leg of the traffic pattern, he noticed an “immediate low rotor speed,” a loss of engine power, and the helicopter yawed to the left. The pilot increased power; however, both the engine and rotor rpm continued to decrease rapidly. The pilot lowered the collective to regain and maintain rotor rpm and initiated an autorotation to an agricultural field. The helicopter landed hard, and a rotor blade severed the tail boom.

The pilot stated that he experienced the same malfunctions twice during a flight about 3 months before the accident (low rotor speed and loss of engine power). During this flight, he was able to land the helicopter without incident.

A postaccident examination of the helicopter revealed faulty wiring to the engine governor. Because of the faulty wiring, the governor was likely unable to sense rotor and engine rpm and make the necessary adjustments to keep rotor rpm constant, resulting in a loss of engine power.

Text from the NTSB. Open the NTSB docket for WPR19LA002 for the full record.