NTSB Factual Report

On October 27, 2001, at 0930 central daylight time, a Meester HP-14 glider, N8833, piloted by a commercial pilot, sustained substantial damage during an off-airport landing near the Sylvania Airport, Sturtevant, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot, the sole occupant, sustained serious injuries. The flight departed the Sylvania Airport for a local flight and was returning to land at the time of the accident.

A witness to the accident reported he was the tow-pilot for the accident glider on the accident flight. The witness stated he towed the glider to 3,000 feet above ground level (agl) and the glider released without any problems. The witness reported that after the successful tow he returned to the departure airport. The witness stated he observed the glider enter the traffic pattern for runway 26 on a 45-degree entry to the downwind leg. The witness reported the glider was, "... at or very slightly below the normal traffic pattern altitude (800 ft agl)... ." The witness stated, "A little past midfield, [the pilot] made a left 360 degree turn and re-entered the downwind leg." The witness estimated that the glider was approximately 500 feet agl when it reentered the downwind leg. The witness reported, "The turn to base leg looked normal but [the pilot] overshot the final approach to the south. [The pilot] turned toward the final approach course and was headed back towards the approach end of the runway, coming in on about a 20-30 degree angle. At the point I expected her to make a left turn and line up on final, she continued to turn to the right and exited my view going roughly downwind eastbound. My estimate is that she was 100 to 150 feet agl as she proceeded through the final approach course."

According to the pilot's written statement, she was towed to 3,000 feet agl without any anomalies and after the aircraft released from the tow she completed a right clearing turn. The pilot reported turns to the right were without anomalies and the turns to the left were "stiff and resistant". The pilot stated, "Aircraft did not respond as usual. Airspeed did not equate to attitude." The pilot reported, "There was a sound of air being forced through a crevice or a hole." The pilot described the sound as a "hum or whine". The pilot reported she elected to turn back to the airport and enter a right traffic pattern for runway 26R. The pilot stated she executed a right and left turn while on the downwind leg and the turn to the left was "stiff, sluggish and slow to respond." The pilot reported during a right turn to the final approach course she was unable to stop the right turn using left control stick input. The pilot elected to land on a rough and uneven agricultural field adjacent to the airport. The pilot reported she had 163 hours in gliders, of which 9.5 hours were in the same make and model as the accident glider.

According to the Soaring Flight Manual, as published by the Soaring Society of America, "[A turning slip] is accomplished by applying rudder opposite to the turn while maintaining the bank angle with aileron." The manual states, "Caution should be exercised during slips since the airspeed indicator is not accurate. The reason for this situation is that air does not flow directly into the pitot tube in uncoordinated flight. References, such as the position of the nose with respect to the horizon, and sound are usually more reliable."

An inspector with the Federal Aviation Administration (FAA) performed the post-accident inspection of the glider. The FAA inspector reported, "To the extent possible, I examined all the flight controls for control continuity, and found no abnormalities."

NTSB Probable Cause

The restricted movement of the aileron control system for undetermined reasons.