On August 15, 1989, a Schleicher ASW-20BL (registration N300Y) was involved in an aviation accident near Minden, NV. Investigators recorded the probable cause as: MISUNDERSTOOD EMERGENCY PROCEDURES, THE GLIDER PILOT RELEASED FROM THE TOW WHICH RESULTED IN A HARD LANDING. THE PILOT'S PREFLIGHT OF THE GLIDER AND RADIO COMMUNICATIONS WERE INADEQUATE BEFORE AND DURING THE FLIGHT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a local pleasure flight, a glider pilot misinterpreted the tow pilot's transmission and rudder wag as a release signal, releasing at about 100 feet AGL and resulting in a hard landing.
Incident
During a local pleasure flight, a glider was being towed by a tow plane. While still in tow, the tow pilot transmitted a message to the glider pilot. The glider pilot could not understand the transmission and shortly thereafter noticed that the tow plane's rudder was wagging. Interpreting this as a signal to release, the glider pilot released from the tow at approximately 100 feet above ground level (AGL). This premature release resulted in a hard landing.
Details
Later, the glider pilot was informed that the transmission and rudder wag were intended to notify him that the glider's spoilers had deployed. The glider pilot had not checked during the preflight inspection whether the spoilers had been locked. The spoilers' deployment during tow likely prompted the tow pilot's notification attempt.
Aftermath
The hard landing concluded the flight. No further details were provided regarding injuries or damage.
