On January 31, 1993, a Grumman American AA-5 (registration N1383R) operated by David Spiegelthal was involved in an aviation accident near Lanham, MD. Investigators recorded the probable cause as: Total blockage of the left and right fuel vent lines by insect nests, which terminated the flow of fuel to the engine. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane lost total engine power about 10 minutes after takeoff at 1,400 feet MSL. The pilot executed a forced landing in a residential area, intentionally stalling at 200 feet to avoid obstacles. Investigation revealed insect nests completely blocked both fuel vent lines.
Incident Overview
Approximately ten minutes after departure, while climbing through an altitude of 1,400 feet above mean sea level, the airplane experienced a complete loss of engine power. The pilot was unable to restart the engine and initiated a forced landing in a residential area. Due to the congested nature of the terrain, the pilot could not maneuver the airplane to find a suitable clear area. To avoid striking a house or powerline, the pilot deliberately stalled the airplane at about 200 feet above the ground. The airplane then descended vertically approximately 200 feet and came to rest on a road.
Examination Findings
A thorough post-accident examination of the wreckage revealed that both the left and right fuel vent lines were completely obstructed. The blockages were caused by insect nests located at the wing root section of each vent line. These obstructions terminated the flow of fuel to the engine, leading to the total loss of power.
Probable cause
Total blockage of the left and right fuel vent lines by insect nests, which terminated the flow of fuel to the engine.