Amateur-built AEROMASTER N55J accident near Sulphur Springs, Texas

Probable cause

A total loss of engine power for reasons that could not be determined because postimpact damage precluded a thorough examination of the airplane. Contributing to the accident was the pilot's failure to maintain control following the loss of engine power, which resulted in the airplane exceeding its critical angle of attack and experiencing an aerodynamic stall/spin.

NTSB analysis

The private pilot had purchased the experimental amateur-built airplane about 2 weeks before the accident. The previous owner had provided the pilot with a 1-hour familiarization flight, during which he repeatedly told the pilot not to lean the mixture control on takeoff. During takeoff on the familiarization flight, the pilot leaned the mixture, resulting in a total loss of engine power while still on the runway. After advancing the mixture control, the engine restarted and they continued the flight. The pilot again leaned the mixture control at altitude, which resulted in the engine running rough.

Following the familiarization flight, the pilot departed to an unknown destination, and, during that flight, he landed at an en route airport due to a rough-running engine. Maintenance personnel at the airport found that the airplane had 26 mechanical discrepancies and was unairworthy. Two mechanics and two experimental aircraft builders told the pilot that the airplane was unsafe and should be taken apart and "trailered" home. The mechanic repaired a leaking brake, replaced all of the spark plugs, serviced the oil, and ran the engine. During the postmaintenance engine run, the magnetos were checked and appeared to function properly, and the engine ran smoothly. The pilot then departed on the accident flight. The mechanic stated that the airplane experienced a total loss of engine power about 200 ft above ground level and the airplane entered a left turn, which subsequently developed into a stall/spin. The airplane completed about 1/4 turn in the spin before impacting terrain.

Postaccident examination was precluded by damage sustained in the postcrash fire. The investigation was unable to determine if the loss of engine power occurred due to the pilot's improper manipulation of the engine controls, or if there was a mechanical malfunction.

Text from the NTSB. Open the NTSB docket for CEN15LA329 for the full record.