The plans-built single-seat Bowers Fly Baby 1A had been built about eight years before the accident by another individual, who had flown it about 30 hours before it was purchased by the current owner/pilot.
In the year since the purchase, due to the low build-quality of the airplane, the pilot had made several modifications and repairs.
The accident flight was the pilot’s fifth flight in the airplane. Review of the pilot’s flight logbook indicated that his most recent flight review occurred about seven years before the accident and that he had flown only 15 hours in the two years before the accident.
A witness reported that shortly after takeoff, when the airplane was about three miles from the airport in Mariposa, Calif., the engine began making a sound as if power was intermittently being interrupted.
The nose of the airplane began to pitch up aggressively as it flew out of view.
The wreckage location, wreckage distribution, and impact signatures indicated that the airplane struck the ground in a steep nose-low attitude, consistent with an aerodynamic stall event. The pilot was killed in the crash.
Post-accident examination of the carburetor revealed multiple maintenance-related discrepancies, any one of which could have resulted in the loss of engine power.
Additionally, before the accident, the pilot reported to a friend that the airspeed indicator was not reliable and that the airplane exhibited roll control anomalies. Both of these conditions would have hindered the pilot’s ability to safely operate the airplane.
The NTSB determined the probable cause as the partial loss of engine power due to an improperly maintained carburetor and the pilot’s subsequent failure to maintain aircraft control.
NTSB Identification: WPR14FA165
This April 2014 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.