Accident Description
According to the pilot, the takeoff was initiated on a 1,800-foot soft sod runway. After a ground roll of approximately 800 feet, the airplane became airborne. As it passed over a fence, the pilot noticed that the climb performance was deteriorating. A scan of the instruments showed the tachometer indicating 2,100 revolutions per minute (RPM), whereas the normal takeoff RPM would have been 2,500. The airplane subsequently crossed a river and struck the opposite bank.
Passenger Observations
Two passengers aboard the airplane stated that they believed the pilot had used most of the runway during the takeoff roll.
Post-Accident Investigation
A post-accident investigation revealed no evidence of pre-impact mechanical failure or malfunction. The propeller was examined and disassembled. The propeller blades were found at a pitch setting of approximately 20.5 degrees. The normal pitch setting for takeoff and climb is 12.5 degrees. No explanation for the higher pitch setting was discovered during the investigation.
Computer Simulation
A computer simulation of the accident scenario indicated that, under the conditions and power described by the pilot, the blade angle would have been approximately 18.5 degrees.