Pilot Debrief

WILLIAMS MYRON G BOWERS FLY BABY 1A near Mariposa, CA — 2014-04-11

Final reportWPR14FA165
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Date
2014-04-11
Location
Mariposa, CA, USA
Airport
MPI
Aircraft
WILLIAMS MYRON G BOWERS FLY BABY 1A
Registration
N6054Q
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Climb

Probable cause

The partial loss of engine power due to an improperly maintained carburetor and the pilot's subsequent failure to maintain aircraft control.

NTSB narrative

The plans-built single-seat airplane had been constructed about 8 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 to the airplane. 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 7 years before the accident and that he had flown only 15 hours in the 2 years before the accident. A witness reported that shortly after takeoff, when the airplane was about 3 miles from the airport, 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. Postaccident 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.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have used carburetor heat to prevent engine power loss.

NTSB coding

Evidence available

  • 10 docket documents
View NTSB final reportView NTSB docket

Docket documents10

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