ES 52/1 Kookaburra Glider, VH-GHS, R.A.A.F. Base Pearce, WA, 15 February 1970

The glider was prepared for a winch launch on Runway 18, using 5,000 feet of cable. By the time the glider was ready for launching the wind had backed from 180 degrees to approximately 090 degrees, with a mean speed of 14 knots. The instructor appreciated this and planned to land on Runway 05 for subsequent launches. With both instructor and student aboard, the aircraft exceeded by 82 pounds the maximum permissible take-off weight. The first attempt to launch the glider was abandoned because it drifted across the runway. During the second attempt the glider was still on the ground after rolling about 1000 feet. The instructor used elevator control to lift the glider into the air at 45 m.p.h., 3 - 5 m.p.h. below the normal separation speed. A height of 20 - 30 feet was reached with an airspeed of about 50 m.p.h., but the winch speed was low and the airspeed began to decay. A signal from the pilot calling for an increase in winch speed produced no result and the tow cable was released at about 45 m.p.h. and the nose of the glider lowered, but the speed did not increase and the glider was landed heavily, in a near stalled condition, causing substantial damage to the lower mid section of the fuselage.