Piper PA 22-150 N4356A accident near Fountain Hills, Arizona

Probable cause

A partial loss of engine power for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.

NTSB analysis

The private pilot reported that, after a preflight inspection and engine run-up revealed no anomalies, he and a passenger departed, circled a nearby mountain, then descended to an altitude about 750 ft above ground level. Shortly thereafter, the engine experienced a partial loss of power. The pilot attempted to restore engine power, but was unsuccessful, and he elected to land the airplane on a dry wash. As the airplane touched down, the right main landing gear sank into the dirt, and the airplane made a sharp turn to the right. The airplane impacted a tree and came to rest nose down. The atmospheric conditions at the time of the accident were not conducive to the formation of carburetor icing. A postaccident engine examination and test run revealed no anomalies that would have precluded normal operation; therefore, the reason for the loss of partial engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR16LA079 for the full record.