Amateur-built SONEX WAIEX N461MM accident near Palm Coast, Florida

Probable cause

A total loss of engine power during cruise flight for reasons that could not be determined due to the postaccident condition of the engine and its associated fuel and ignition systems.

NTSB analysis

The accident flight was the pilot's first solo flight in the experimental amateur-built airplane, which had not been flown for about 6 months. The airplane departed without incident; however, about 10 minutes after takeoff, it experienced a total loss of engine power (as reported by a witness) and subsequently impacted in a tidal marsh. Postaccident examination of the airplane, which included disassembly of its engine, did not reveal evidence of any preimpact mechanical malfunctions; however, the fuel system was completely compromised and the majority of the ignition system was not recovered. While the airplane had a reported history of fuel system issues, the logbooks were not located, and the airplane's maintenance and operational history could not be verified. Therefore, the reason for the loss of engine power could not be determined.

The pilot had no record of a Federal Aviation Administration medical certification examination. A limited autopsy did not identify any natural disease. Toxicology testing detected ethanol in muscle (0.082 gm/dl) and liver (0.082 gm/dl), as well as n-butanol and n-propanol. While the distribution of ethanol in the muscle and liver is not inconsistent with ingestion, decomposition and the finding of n-butanol and n-propanol in tissues suggests that some or all of the ethanol came from microbial action after death.

Additionally, diphenhydramine and citalopram and its metabolite were detected in liver and muscle. Although diphenhydramine can cause significant psychomotor impairment, no blood was available for analysis, thus it could not be determined if the pilot was impaired by the diphenhydramine at the time of the accident. Citalopram is an antidepressant that is not generally considered impairing; however, it was unknown if the pilot's underlying psychiatric condition was under control.

Text from the NTSB. Open the NTSB docket for ERA15FA003 for the full record.