Circumstances:

The pilot had positioned at Tindal from Victoria River Downs and embarked eight passengers for Delamere. On arrival at Delamere, the nose gear would not extend. Despite all attempts to extend the gear, the landing gear position indicator continued to indicate an unsafe position for the nose gear. The pilot elected to return for a landing at Tindal. A flypast of the tower revealed that the main gear wheels and nose gear doors were extended but the nose gear was still fully retracted. The pilot decided to land with the gear in that configuration. A successful landing was carried out and the runway under the aircraft was foamed when the aeroplane came to rest. A subsequent inspection revealed that the front right-hand nose gear door was installed incorrectly. This door had been installed in a position one hinge serration rearward of its correct position. That door then fouled the rear right-hand nose gear door which in turn prevented the nose gear leg from extending. On removal of the front right-hand nose gear door, the nose gear leg fell free and locked into the DOWN position. The aircraft logbook showed no entry for the removal and replacement of the nose gear door, but the aircraft showed evidence of having been recently repainted.

Significant Factors:

The following factors were considered relevant to the development of the incident:

1. Incorrect installation of the front right-hand nose gear door.

2. A fouling of the nose gear doors prevented the nose gear leg from extending.

3. Inadequate supervision of maintenance.

The aircraft departed Sydney on 8 August 1987, with the pilot and eight French tourists, for a twelve day Air Safari. The trip was uneventful until about 35 km west of Mt Isa, when the left engine failed during the descent. The pilot did not attempt to lower the landing gear and flap until the aircraft was on final approach. However, the landing gear did not extend. A go-around was carried out and on the subsequent circuit the pilot attempted to release the hydraulic hand pump so that he could manually pump the gear down. He was unable to release the handle. This fact, combined with an indication of rising temperatures on the operating engine necessitated a reduction in power on that engine, with a resultant loss of aircraft performance. The pilot then decided to carry out a "wheels-up landing" on the grassed area adjacent to the main runway. During the approach and landing the cowl flaps on the operating engine remained closed. An inspection of the aircraft revealed that the engine failed due to the separation of the induction system when the number 3 cylinder hold down bolts broke. These bolts failed as a result of fatigue probably as a result of the studs either not being torqued correctly at installation or becoming loose in service. The landing gear failed to extend by the normal method due to too low a hydraulic pressure possibly caused by low fluid level in the reservoir. It was found that the hydraulic hand pump handle required a two-handed effort to release it. This was due to it being clogged with dirt and old grease.

Circumstances:

The pilot had engaged in gliding activities for more than thirty years. These activities were interrupted in December 1987 when he underwent coronary by-pass surgery. On receipt of a medical clearance from his coronary specialist, the pilot resumed flying gliders in February 1989. He had since accumulated 31 flights of which 18 were solo. On the day of the accident, the pilot arrived at the airstrip at about 0930 hours and during the day assisted with glider launch and recovery operations. Late in the afternoon the pilot was authorised by the duty officer for a solo flight. After a winch launch in a northerly direction in light wind conditions, the glider was observed to perform several steep turns before positioning for a right hand downwind leg for a landing in a northerly direction. The pilot reported his position by radio on the downwind leg in accordance with the gliding club's standard procedures. The flight was witnessed by numerous club members who were generally located at the southern end of the airstrip. They reported the approach appeared normal until the glider was established on base leg. The turn onto the final approach was delayed such that the glider lined up on the western side of the strip which is reserved for winch launches. Soon after, when the glider was at an altitude of about 150 feet above ground level, it commenced a turn to the left. The glider levelled out on a south-westerly heading and then entered a climb, from which it apparently stalled, and dived from view behind trees. The wreckage was found in timbered country about one kilometre from the southern end of the gliding strip. The wreckage distribution suggested the glider had rolled inverted and dived near vertically into the ground. A technical examination revealed no evidence of any pre-existing fault or defect. The manoeuvres following the turn onto final approach were consistent with the pilot being incapacitated. The autopsy revealed the pilot had suffered a heart attack.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. The pilot was incapacitated when he suffered a heart attack.

2. Loss of control in flight due to pilot incapacitation.

The pilot had been operating the glider at this strip for several days, being launched for each flight by an aero-tow aircraft. The grass at the strip was about 15 centimetres long, and was relatively dense. The weather conditions for this flight were fine, with a light and variable wind. On takeoff, as the tug aircraft and glider accelerated the right wing tip of the glider contacted the grass. An attempt by the pilot to raise the wing was unsuccessful and the glider groundlooped. During this groundloop the tow line back-released. The particular glider was equipped with a belly tow point, with no provision for a tow point on the nose. With the wings level, there is about 30 centimetres clearance from the wing tips to the ground. This accident was not the subject of an on-scene investigation.

Circumstances:

During the landing roll, the tail wheel springs failed, and the tail wheel fell from the aircraft. This resulted in a loss of directional control as the aircraft weather-cocked. The aircraft came to rest against the boundary fence. The mode of failure has not been established.

The pilot reported that the take-off on runway 17 proceeded normally until immediately after the gear was selected up. At this point the aircraft pitched up and rolled to the left. The pilot pushed the auto-pilot release button on the control column and heard the release annunciator sound, however he noted that the yaw damper and auto-pilot annunciators were illuminated. He also noted the elevator trim wheel moving and shortly thereafter the stick shaker began to operate at an aircraft speed of about 115 knots. The aircraft was manoeuvred for a successful landing on runway 26. It was determined that water had entered the auto-pilot computer via a faulty seal on the electronics compartment door. Prior to take-off the pilot armed the flight director system in the indicated air speed and heading modes. During the take-off run the auto-pilot engaged, wound the elevator trim nose up and commanded a left turn. The pilot managed to overpower the auto-pilot inputs by applying extremely high forces to the control column, but in doing so was unable to withdraw one hand from this task to trip the circuit breaker controlling power to the auto-pilot.

The pilot was making his second solo flight at the completion of a one-week gliding course. On the landing approach the glider was seen to be undershooting with the speed brakes extended. As the approach continued the undershoot increased but the speed brakes remained extended. The glider struck a fence, bounced across a road and struck a second fence at the aerodrome boundary. A fence wire rode over the nose, shattering the canopy and decapitating the pilot. No contributory fault was found with any of the components of the glider. The pilot misjudged the final approach.

Circumstances:

During a period of circuit training, the instructor initiated a practice forced landing while on the downwind leg. The student flew the circuit, but during the turn onto final approach, allowed an undershoot situation with low airspeed to develop, resulting in a heavy landing on one main wheel. The instructor had not adequately monitored the airspeed and did not allow for the prevailing conditions which were reported as calm with some sink on final approach.

Circumstances:

At the completion of a cross-country flight, the pilot attempted an out landing on a cleared area about 1 kilometre north of the aerodrome boundary. The approach path was in a southerly direction and took the glider between two large hangars, which were off the aerodrome. Powerlines which the pilot did not see, ran east west beside a road between the hangars and the outlanding field. The glider collided with these powerlines, separating the tailplane from the fuselage and the canopy was shattered.

Circumstances:

The pilot reported that he had carried out several take-offs and landings on the same stretch of beach immediately before the accident. During the landing roll the aircraft encountered a soft patch of sand and nosed over, bending the main spar and some ribs.