On September 17, 1989, an Aeronca 7AC (registration N83732) was involved in an aviation accident near Semmes, AL. Investigators recorded the probable cause as: IMPROPER REPLACEMENT OF THE FUEL CAP GASKET BY THE PILOT, WHICH RESULTED IN A BLOCKED FUEL CAP VENT AND FUEL STARVATION. TREES IN THE EMERGENCY LANDING AREA CONTRIBUTED TO AIRCRAFT DAMAGE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After replacing a fuel cap gasket with a non-identical part, a pilot experienced engine power loss during climb. An emergency landing resulted in a tree strike. Post-accident inspection revealed the new gasket blocked the fuel cap vent.
Maintenance and Previous Flights
Following an annual inspection, the pilot chose to replace a fuel cap gasket that had been previously ordered. During the replacement, he observed that the new gasket was not an exact match for the original but considered it acceptable. After replacing the gasket, the pilot refueled the aircraft and conducted several takeoffs and landings without incident. Approximately 30 minutes of flight time elapsed before a passenger boarded the aircraft.
Power Loss and Emergency Landing
Upon takeoff with the passenger on board, the engine lost power during the initial climb. The pilot executed an emergency landing but was unable to stop the aircraft before it struck trees.
Post-Accident Discovery
After the accident, the pilot inspected the aircraft and discovered that the new gasket had blocked the fuel cap vent. He also noted that during the landing sequence, the fuel cap became dislodged enough to allow air to re-enter the tank, causing the engine to restart.