SEA05LA009 · Cessna A185F

This was the pilot's first attempt at taking off uphill on the 2,300-foot private airstrip, which was estimated to be an upgrade of between 6 and 8 percent. After taxiing to the north end of the airstrip and noticing a strong right-quartering gusty headwind, the pilot selected 20 degrees of flaps and applied full power. The takeoff roll was normal, with the first 1,000 feet being on level ground, the second 1,000 feet being uphill, and the last 300 feet being on level ground; a fence bordered the end of the airstrip. The pilot, anticipating a longer-than-usual ground roll consistent with the uphill departure, applied back pressure on the control yoke with 300 feet of available runway remaining, but the aircraft did not lift off the ground. He then added another 10 degrees of flaps, which he said was in accordance with the airplane's soft-field takeoff procedures. At about the same time the airplane was crossing the fence line at the end of the runway, the pilot heard the sound of an impact. After the airplane became airborne the engine immediately developed a vibration, prompting the pilot to make a right 180 degree turn back to the airstrip. Approximately one-half to two-thirds of the way through the turn the engine lost all power and quit. The pilot managed to land the airplane in a pasture which bordered the departure airstrip on the west, spinning around 180 degrees and sliding backwards before coming to rest in an upright position. The airplane sustained substantial damage to both wings, the vertical stabilizer, and the fuselage. The exhaust stack exhibited impact damage which creased the bottom one-third of the component to the extent that the exhaust area opening was almost entirely closed. The aircraft owner's manual notes that soft-field takeoffs are performed with 20 degrees of flaps, and flap extension to 30 or 40 degrees is not recommended for takeoff.

Verbatim NTSB analysis and probable cause from the NTSB dataset