SEA05LA009

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.

On October 17, 2004, about 1130 Pacific daylight time, a Cessna A185F, N101AM, was substantially damaged following a forced landing near White Bird, Idaho. The airplane was registered to and operated by a private individual. The certificated private pilot and his sole passenger received minor injuries. Visual meteorological conditions prevailed for the personal flight, which was being conducted in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight was originating from the pilot's private airstrip at the time of the accident.

In a telephone interview with the NTSB investigator-in-charge (IIC), and according to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that he taxied to the north end of the 2,300-foot airstrip and noticed a strong right-quartering gusty headwind. The pilot stated that he selected 20 degrees of flaps and applied full throttle and full RPM (2850). The pilot reported the takeoff roll was normal, with the first 1,000 feet of the ground roll being on approximately level ground, "...followed by a 1,000-foot uphill stretch and a final 300-foot level section." The pilot stated the tail came up on the uphill portion of the airstrip and the airspeed was nominal during the last 300 feet, with a fence bordering the end of the airstrip. The pilot reported, "We had anticipated this longer-than-usual ground roll; it was consistent with the uphill departure necessitated by the strong southwest wind." The pilot reported he added backpressure during the last 300 feet to clear the fence at the end of the airstrip, "...but the aircraft did not lift off as expected." The pilot reported trying to get airborne by adding another 10 degrees of flaps, which he stated was in accordance with the soft-field takeoff procedures. The pilot related, "The nose was up by then, but we heard an impact as we crossed the fence line." The pilot reported the engine immediately developed a slight vibration, "...so I executed a climbing turn to the right to return to land. The engine quit without warning about half to two-thirds of the way through the 180 degree turn." The pilot reported that he was able to set up a gliding approach to a pasture, which bordered the airstrip on the west. After touching down the airplane's right main landing gear separated, followed by a nose strike. The pilot reported the airplane then spun around 180 degrees and slid backwards approximately 100 feet before coming to rest upright heading in a southeasterly direction.

The pilot reported that both main landing gear, the tail wheel, both entry doors, and the propeller had separated from the airplane. The tail section and both wings were bent and twisted. The pilot said he felt the engine quit as a result of the airplane impacting the fence during takeoff. The pilot also stated that there were no anomalies detected with the airplane prior to the attempted takeoff.

A certificated Federal Aviation Administration (FAA) airframe and powerplant mechanic examined the exhaust stack, which was impact damaged. The component was void of any dirt or ground impact signatures and remained elevated above ground level next to the right main landing gear. The deformation to the exhaust stack was such that the bottom one-third of the stack exhibited a lateral creased/closed off appearance.

The IIC calculated the density altitude at the time of accident to be 5,968 feet. An FAA inspector reported to the IIC that he estimated the uphill slope of the runway to be between 6 and 8 percent. The inspector also reported that the pilot told him this was the first time he had ever attempted an uphill takeoff from his private airstrip.

As noted under the TAKE-OFF section of the Cessna 185 Owner's Manual, "Soft-field take-offs are performed with 20 degrees of flaps. Flap deflections of 30 degrees and 40 degrees are not-recommended for take-off."