On March 1, 1992, a Mooney M20C (registration N6748U) operated by Hannon, Fred W. was involved in an aviation accident near Charleston, SC. Investigators recorded the probable cause as: THE BLOCKED FUEL VENT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot experienced engine power loss, attempted to switch fuel tanks, and performed an emergency landing in trees. Examination revealed a blocked fuel vent and mismatched fuel levels.
Incident Overview
A pilot encountered a loss of engine power during flight and attempted to change fuel tanks. The engine briefly regained power before losing it again. The pilot subsequently executed an emergency landing in a group of small trees.
Post-Accident Examination
Inspection of the aircraft after the landing revealed that the right wing fuel tank was empty, while the left wing fuel tank contained approximately one quarter of its capacity. Further examination of the left wing tank identified a blockage in its fuel vent. The vent was obstructed by nesting dirt daubers, and air could not be forced through it.
Findings
The combination of an empty right tank and a partially filled left tank, coupled with the blocked vent, was noted. No other anomalies were reported in the examination.