Accident Details
The airport elevation was 1,071 feet msl, and the density altitude at the time was approximately 2,487 feet msl. The airplane was performing a high gross weight normal takeoff from a 3,640-foot-long asphalt runway at 79 degrees Fahrenheit. It became airborne at 80 knots indicated airspeed (KIAS). The nose rose higher than needed, most likely due to the elevator trim setting, requiring the pilot to apply forward pressure on the yoke. The airplane accelerated to 90 KIAS but did not initially climb out of ground effect, then began a very slow climb. During the slow climb, the pilot elected to retract the landing gear and the 10 degrees of flap extension. The airplane subsequently sank at the end of the runway, prompting the pilot to abort the takeoff.
Engine Examination
A test run of the engine revealed that it was producing approximately 4.5 percent less than the maximum brake horsepower (BHP). Examination showed that the throttle adjustment was not correct per a manufacturer service instruction. During a recent annual inspection, the throttle had been adjusted, but there was no record of the manufacturer service instruction being utilized.
Flap Retraction Procedures
The make and model airplane flight manual (AFM) checklist did not specify climb performance with regard to flap retraction during a normal takeoff. However, the FAA Airplane Flying Handbook suggested that flaps should be retracted once a positive rate of climb is established. For short field takeoffs, the handbook stated that flaps and landing gear should remain in the takeoff position until clear of obstacles and Vy has been established. When Vy stabilizes, the gear and then the flaps should be retracted, with flaps raised in increments to avoid sudden loss of lift and settling of the airplane. Vy for the accident airplane was 110 knots.