Amateur-built W10 N625JS accident near San Antonio, Texas

Probable cause

An in-flight fire and subsequent total loss of engine power for reasons that could not be determined due to extensive impact and fire damage, followed by a loss of airplane control.

NTSB analysis

The commercial pilot was conducting a personal flight in his amateur-built airplane to accumulate additional flight time on the overhauled engine. A witness reported that he initially saw the airplane flying about 1,500 ft above the ground with no noticeable engine issues; however, as the airplane flew past his position, the engine began "struggling" for about 10 seconds before power was lost. The witness stated that the airplane was on fire as it descended into terrain. Another witness reported seeing fire coming from the bottom of the airplane while it was inflight. He also stated that the airplane briefly pitched up before it suddenly banked and descended nose down into terrain. The airplane was destroyed by impact forces and fire. A functional test of the engine and a comprehensive examination of the airplane's fuel system were not possible due to impact and fire damage. A partial teardown examination showed no evidence of a mechanical malfunction that would have precluded normal operation during the flight.

Text from the NTSB. Open the NTSB docket for CEN18FA139 for the full record.