Casualties unknown

Aircraft Crashes After Fuel Leak Reported; Marijuana Found in Pilot-Rated Passenger (N601MK)

Livermore, CA, US

On May 20, 1994, an Aero Commander 500A (registration N601MK) operated by Mellor, Michele, M. was involved in an aviation accident near Livermore, CA. Investigators recorded the probable cause as: A FUEL SYSTEM LEAK, INADEQUATE PREFLIGHT BY THE PILOT (PIC), AND BY THE NON-FLYING PILOT/PASSENGER INTENTIONALLY ALLOWING OPERATION OF THE AIRCRAFT WITH A KNOWN DEFICIENCY (FUEL LEAK). This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

An aircraft that had not flown for two years crashed after a reported fuel leak. The pilot-rated passenger tested positive for marijuana.

Incident Overview

An aircraft that had been inactive for two years was involved in an accident shortly after takeoff. Pre-flight inspection revealed evidence of fuel leaking from drain holes in the left wing root, just aft of the main cabin door. A mechanic brought this to the attention of a pilot-rated passenger. Despite the report, the aircraft departed with the pilot (PIC), the aircraft owner, and another passenger/mechanic on board.

Flight and Accident Sequence

Approximately 14 minutes after takeoff, radar data indicated the aircraft transitioning from a climb to a descent while executing a 180-degree turn. Witnesses observed smoke and flames trailing from the aircraft. Subsequently, the aircraft struck trees and power lines before crashing in a small flat field within hilly terrain.

Post-Crash Examination

Examination of the wreckage revealed melted aluminum spatters on the leading edge and underside of the left horizontal stabilizer. Additionally, focalized fire damage was noted on the cabin behind the drain holes in the left wing root.

Toxicology Findings

Toxicological analysis detected tetrahydrocannabinol carboxylic acid (marijuana) in the blood (0.004 μg/mL) and urine (0.010 μg/mL) of the pilot-rated passenger.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001206X01388. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.