SEA00LA169

The homebuilt gyroplane pilot reported that while in cruise, approximately 500-1,000 feet above ground, he lost directional control of the aircraft. He reported that his only method of control was to cross-control with full left cyclic which brought the gyroplane to a flat attitude in a spiral turn to the right. Unable to stop the spiral, he reduced throttle and initiated a spiraling descent to ground impact. A post-crash fire destroyed the gyroplane. Examination of the wreckage revealed no apparent discontinuity in the gyroplane's rudder controls. A horizontal stabilizer had been added to the aircraft which, according to the owner/builder, benefited the in flight stability of the gyroplane.

On August 21, 2000, approximately 0920 Pacific daylight time a Clearwaters RAF 2000 homebuilt gyroplane, N61376, owned and being flown by a private pilot, was destroyed during an in-flight collision with terrain approximately six nautical miles southeast of Leahy, Washington. The pilot and passenger both sustained serious injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal, was operated under 14CFR91, and originated from Chelan, Washington, and was destined for Coulee City, Washington.

According to Douglas County Sheriff's personnel, the pilot reported that he was in cruise approximately 500-1,000 feet above ground when he lost rudder control. Unable to maintain directional control, he entered into an autorotation to an emergency landing. The rotorcraft caught fire during the touchdown/impact and was destroyed. Both occupants were airlifted to a hospital in Wenatchee, Washington, after escaping the aircraft. The pilot notified Sheriff's authorities by calling 911 at 0932.

The pilot subsequently reported on NTSB Form 6120.1/2 that while trouble shooting an electrical problem in flight he applied rudder to make a heading correction and noticed that the "controls did not feel right." He then applied left rudder and the gyroplane continued to turn right and began a right bank. Unable to correct for the right bank the "only method was to cross control with full left cyclic which brought [the] aircraft to a flat attitude in a spiral turn to [the] right. He then checked the rudder pedals to verify that he was actually applying left rudder and confirmed that the controls were in that position. Unable to stop the right spiral, which was aggravated with the addition of power, he reduced throttle and initiated a spiraling descent to ground impact.

An inspector from the Federal Aviation Administration's (FAA) Spokane, Washington, Flight Standards District Office (FSDO) examined the wreckage at the accident site. He subsequently reported in a telephonic interview that the aircraft had been destroyed by fire with much of the airframe section melted (refer to photograph 1). He stated that the rudder control cables were successfully traced for continuity from the center cabin area (where they were entrapped in melted aluminum), to the vicinity of the rudder panel (refer to photograph 2). At the rudder panel, both cables were observed to terminate at their melted aluminum attach fittings, which were no longer attached to the nearby rudder panel (refer to photograph 3). The inspector also reported that the small engine driven drive gear used to engage the main rotor assembly (refer to photograph 4) was observed at the site to be partially engaged to the gear teeth on the larger rotor drive gear (refer to photograph 5). Additionally, the fire damaged remains of a horizontal stabilizer was observed lying on top of the rudder/vertical stabilizer (refer to photograph 6). No further examination of the horizontal/vertical stabilizer assembly was conducted. The wreckage was released to the owner/builder following the FAA's on-site examination. It was subsequently disposed of by the owner/builder.

Documentation provided by the owner/builder to the FAA's Spokane FSDO showed that the gyroplane had been modified with the addition of a fixed horizontal stabilizer. This stabilizer had been mounted forward of the rudder panel and on either side of the gyroplane's vertical stabilizer. Both left and right stabilizer panels were mounted to the vertical stabilizer by means of two metal "L" brackets. Additionally, a support rod anchored each horizontal stabilizer at a midspan location to the bottom of the vertical stabilizer (refer to ATTACHMENT OB-I). The owner/builder indicated on the documentation that the "modification benefits the in flight stability of the machine."