Amateur-built MUSTANG II N887QR accident near Jamul, California

Probable cause

Impact with mountainous terrain for undetermined reasons due to the limited evidence that could be collected from the accident scene

NTSB analysis

According to recorded ADS-B data, the pilot departed from a local airport and maneuvered to the east over mountainous terrain. A witness reported that she saw the airplane fly towards Lyons Peak and heard the engine “sputtering.” Shortly thereafter, the airplane disappeared from her field of view and she heard a loud “bang.”

An unsuccessful attempt was made to retrieve the wreckage, which was inaccessible because of the steep, mountainous terrain. Consequently, it was not possible to examine the airframe and engine.

The pilot’s toxicological testing detected ethanol. The extent of trauma, delayed recovery of the pilot’s remains, and the presence of n-propanol and n-butanol make it plausible that some or all of the detected ethanol may have been from postmortem production. However, the positive ethanol result in a single specimen is insufficient to exclude the possibility of alcohol consumption or related impairment. Therefore, the investigation was unable to determine whether ethanol effects contributed to the crash.

Additionally, the zolpidem, commonly used to treat short-term insomnia, and cyclobenzaprine, commonly used to treat muscle spasms, detected in the pilot’s muscle tissue indicated that he had used these medications. However, the limited extent of the autopsy and lack of specific information about the accident sequence prevented the investigation from determining whether the effects of the pilot’s zolpidem and cyclobenzaprine use contributed to the crash.

As reported by friends and family, the pilot was ill during the weeks before the accident. The unknown illness caused him to miss family events and seek medical care. The pilot had a history with chronic lymphocytic leukemia. Whether he was acutely ill at the time of the accident is uncertain, and his autopsy was too limited by injury to be useful for assessing possible underlying conditions (including leukemia).

Given the pilot’s unknown medical condition at the time of the accident and the inaccessible wreckage, which prevented a postaccident examination, the cause of the accident could not be determined.

Text from the NTSB. Open the NTSB docket for WPR23FA007 for the full record.