Casualties unknown

Pilot with High Blood Alcohol Level Crashes Aircraft After Buzzing Witnesses (N7350D)

Quinlan, TX, US

On June 26, 1984, a Piper PA-22-150 (registration N7350D) operated by Harold Thweatt was involved in an aviation accident near Quinlan, TX. Investigators recorded the probable cause as: The pilot's impairment due to alcohol, as evidenced by a blood alcohol level of 0.248%, which led to loss of control during low-altitude maneuvering. 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 crashed in a steep left bank after witnesses reported it buzzing below tree-top level and the engine sounding like it cut out. Toxicology results showed the pilot had a blood alcohol concentration of 0.248%.

What happened

Several witnesses observed the aircraft operating at extremely low altitudes, reportedly flying below tree-top level immediately prior to the accident. During this low-altitude maneuvering, witnesses noted that the engine noise changed character, sounding as though it had cut out. Shortly after these observations, the aircraft impacted the ground while in a steep left bank.

The investigation

A post-accident inspection of the wreckage was conducted to determine the mechanical status of the aircraft prior to impact. This examination revealed no evidence of any pre-impact malfunction or failure of the aircraft systems that would account for the observed behavior.

Findings

The primary factor identified in this accident was the pilot's impairment. A toxicology report performed on the pilot indicated a blood alcohol level of 0.248%, which is significantly above the legal limit for operating an aircraft. This high level of intoxication likely contributed to the impaired judgment and motor skills required to perform low-altitude maneuvers safely.

Safety message

Operating an aircraft under the influence of alcohol poses a severe risk to aviation safety. The pilot's blood alcohol concentration was well above permissible limits, highlighting the critical importance of sobriety in flight operations.

Probable cause

The pilot's impairment due to alcohol, as evidenced by a blood alcohol level of 0.248%, which led to loss of control during low-altitude maneuvering.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X39939. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.