Luscombe 8A N71743 accident near Leander, Texas

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 analysis

The pilot reported that after a seemingly normal takeoff, the airplane would not climb, and he believed that the engine was not producing full power. The airplane impacted trees on the right side of the runway. The pilot stated that before the attempted takeoff, he 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. The pilot then taxied the airplane 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. Postaccident examination revealed no preimpact malfunctions or anomalies that would have precluded normal operation. 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; therefore, it is likely that the airplane’s 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 and the resultant impact with trees on the side of the runway.

Text from the NTSB. Open the NTSB docket for CEN12LA477 for the full record.