Schweizer 269C-1 N504JN accident near Boalsburg, Pennsylvania

Probable cause

A loss of engine power for reasons that could not be determined.

NTSB analysis

The pilot of the helicopter reported that he departed and initiated a slow climb to clear a nearby mountain. The pilot stated that, based on the temperature, dew point, and humidity, he applied carburetor heat; the helicopter’s icing gauge also indicated the need for carburetor heat. As the helicopter approached the mountain, the engine lost partial power, and the pilot maneuvered toward lower terrain to conduct a precautionary landing. The pilot identified a residential cul-de-sac as a landing site and attempted to apply power before touching down; however, the engine did not respond. The helicopter subsequently landed hard from a height of about 4 ft, and the tail boom impacted an embankment, resulting in substantial damage.

A postaccident engine run did not reveal evidence of any preexisting anomalies or failures that would have prevented normal engine operation. The recorded temperature and dew point near the accident site were conducive to the development of carburetor icing at cruise and glide engine power settings; however, the pilot stated that he applied carburetor heat before the loss of engine power. Based on this information, the reason for the loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for ERA25LA044 for the full record.