Aeronca 7BCM N2576E accident near Longmont, Colorado

Probable cause

The pilot's decision to continue the takeoff after observing a partial loss of engine power, the reason for which could not be determined because postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures.

NTSB analysis

The commercial pilot was taking off in the light sport aircraft for a local personal flight. The pilot reported that, while attempting to take off from the 4,799-ft-long runway, he noticed a lower-than-normal engine rpm and that the takeoff roll was significantly longer. Despite the extended takeoff roll and low engine rpm, the pilot chose to continue the takeoff. The airplane lifted off and slowly climbed to about 200 ft above ground level. Due to concerns about rising terrain, the pilot chose to make a forced landing, during which the airplane hit power lines. The airplane then skipped across a road and nosed over.

Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures. Carburetor icing was likely not a factor given the environmental conditions at the time of the accident and the pilot's report of a short taxi time.

Text from the NTSB. Open the NTSB docket for CEN16LA267 for the full record.