CHI02LA013 · Meester HP-14

The glider impacted terrain while attempting an off-airport landing. The pilot reported that she had an aileron flight control problem during the accident flight. The pilot stated turns to the right were made without any anomalies and turns to the left were "stiff and resistant". The pilot reported, "Aircraft did not respond as usual. Airspeed did not equate to attitude." The pilot stated, "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 elected to turn back to the airport and attempt a normal traffic pattern and landing. The pilot reported 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 stated 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. A witness to the accident reported the glider had made both right and left turns while in the traffic pattern. 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."

Verbatim NTSB analysis and probable cause from the NTSB dataset