Amateur-built FLY BABY N59357 accident near Keller, Texas

Probable cause

A partial loss of engine power due to an obstruction of the air intake, as reported by the pilot. Contributing to the accident was the pilot's insufficient preflight inspection.

NTSB analysis

The private pilot conducted a run-up of the experimental airplane's 65-horsepower engine prior to departure, since it had not been flown in the past 90 days. The engine produced full power and the pilot departed the private airstrip. Shortly after takeoff, the engine started to gradually lose power and the airplane was unable to maintain a normal climb rate. The pilot returned to the airport, but had to execute a go-around due to another airplane being on the runway. When he applied full power, black smoke was observed "belching" from the exhaust and the engine power continued to decline. The pilot made a forced landing to a field adjacent to the airstrip and subsequently the airplane sustained structural damage. The pilot reported that there was no air filter installed on the engine and he thought that a nest of mud-dauber wasps had built a nest in the air intake, vibrated loose, and was ingested into the carburetor intake.

Text from the NTSB. Open the NTSB docket for CEN09LA330 for the full record.