On July 23, 1988, a Luscombe 8A (registration N25236) operated by Bransom, Robert M. was involved in an aviation accident near Burleson, TX. Investigators recorded the probable cause as: The pilot's failure to maintain engine power during flight, which resulted from an obstruction in the fuel cap vent caused by a dirt dauber nest. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft experienced engine failure during a forced landing after the pilot applied power on downwind. The cause was traced to a dirt dauber nest obstructing the fuel cap vent.
What happened
The aircraft was operating on the downwind leg of the traffic pattern when the pilot initiated a sequence of actions that led to an engine malfunction. Specifically, the pilot pulled the carburetor heat lever and reduced the engine revolutions per minute (RPM). Upon attempting to reapply power for the approach or go-around, the engine failed to respond as expected.
Despite the loss of power, the pilot managed to execute a forced landing back at the airport. During this emergency maneuver, the aircraft made contact with the airport boundary fence. The impact resulted in damage to the right wing and the tailwheel assembly.
The investigation
Following the accident, investigators examined the aircraft's fuel system components to determine the root cause of the power loss. The inspection revealed a significant obstruction within the fuel cap vent area. Specifically, a nest constructed by a dirt dauber was found lodged in the vent.
Probable cause
The pilot's failure to maintain engine power during flight, which resulted from an obstruction in the fuel cap vent caused by a dirt dauber nest.