Aircraft Collision with Trees During Takeoff from Grass Airstrip (N1418U)

Incident Overview and Conditions The pilot, accompanied by two passengers, landed at a short grass airstrip that had not been used by the pilot previously. After boarding a third passenger, the pilot performed a mental calculation of takeoff performance and elected to take off uphill into the wind. The airstrip was surrounded by tall trees, and the density altitude was approximately 6,000 feet. The aircraft was at or near its maximum gross takeoff weight. ## Takeoff Configuration and Performance The pilot selected 20 degrees of flaps for takeoff and added another 20 degrees during climbout, contrary to flap-use information published in the aircraft's pilot operating handbook (POH). According to performance charts in the POH, the aircraft would have been unable to clear the trees under the given conditions. ## Impact and Engine Findings The aircraft impacted trees at the end of the runway after the pilot attempted to abort the takeoff just before impact. The pilot stated that the engine was unable to produce full power during takeoff. Subsequent testing of the engine did not reveal any preimpact mechanical malfunctions.