Aircraft: Luscombe 8A. Injuries: 2 Minor. Location: Leander, Texas. Aircraft damage: Substantial.
What reportedly happened: The pilot performed an engine run-up, during which he checked the operation of the carburetor heat. However, he did not leave the carburetor heat on at higher power settings for more than a few seconds.
He then taxied from the ramp area to the end of the runway for takeoff. The airplane was operating near or slightly over its maximum gross weight when the accident occurred, and the density altitude was calculated to be 3,347 feet.
According to the pilot, the airplane lifted off normally but would not climb. He believed that the engine was not producing full power. The airplane crashed in trees on the right side of the runway.
The atmospheric conditions at the time of the accident were conducive for serious carburetor icing at glide power settings. Glide power settings yield a throttle angle similar to low power settings used for taxi operations.
Investigators determined it is likely the carburetor accumulated ice after engine run-up and during taxi, which was not detected by the pilot. This subsequent loss of power due to the carburetor ice accumulation resulted in a reduction in climb performance during takeoff.
Probable cause: The partial loss of engine power due to carburetor ice accumulation, which resulted in the airplane’s reduced climb performance and subsequent impact with trees off the end of the runway.
NTSB Identification: CEN12LA477
This July 2012 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.