Loss of control

When the pilot arrived at the destination, he noted that the wind direction indicator showed apparently calm conditions. Almost immediately after touchdown the aircraft began to swing to the right. Attempts to correct the swing were unsuccessful and the left gear leg collapsed. After vacating the aircraft the pilot noticed that there had been a quartering tailwind of about 10 knots during the landing. The pilot was inexperienced on the operation of tailwheel type aircraft, this being his first flight on such a type following a two hour endorsement. This accident was not the subject of an on-site investigation.

During the daily inspection prior to a series of glider towing operations, the pilot noticed that the brake linings were worn. During the landing roll following the third of these operations, the right brake failed and the aircraft ground looped before coming to rest. The brake had failed following the loss of hydraulic fluid from the seal for the brake caliper piston. This was caused by excessive piston travel, associated with severely worn brake linings. When the assembly was dismantled, it was found that the linings had worn completely off the backing plate, and those on the pressure plate were only 1.1 millimetres in depth. Both brake discs were pitted from the effects of corrosion, which would have caused the excessive wear in the linings.

After a normal touchdown a swing to the right developed. The swing was controlled initially with rudder, but when the brakes were applied the pilot was unable to maintain directional control. After the aircraft had swung through about 120 degrees the left wheel was dislodged. The left main axle assembly had separated from the leg because a bolt had failed and a section of the broken bolt had jammed between the brake unit and the brake disc, locking the left wheel. The locked wheel caused the remaining bolts to fail. The bolt that failed was found to have been worn by fretting. The aircraft had only operated 20 hours since servicing was carried out to the gear legs. The failed bolt had not been changed at that service.

CICUMSTANCES The pilot and his passengers were touring in the north-west of Australia. For a number of landings after the DEPARTURE from Parafield the aircraft displayed a tendency to veer to the left side of the runway. The aircraft was checked by a licenced aircraft maintenance engineer and no defects were found. However, the pilot continued to experience the same problem. For the landing at Erong Springs, the aircraft was landed with a slight crosswind from the left. Shortly after the nosewheel was gently lowered onto the runway, the aircraft once again veered to the left. The pilot did not regain control of the aircraft, which ran off the runway and collided with a tree. A thorough inspection was made of the aircraft following the accident but no fault could be found that may have affected the landing performance. The reason for the aircraft diverging to the left during the landing roll could not be determined.

During the aero-tow launch the right wing of the glider contacted the ground and the glider began to veer to the right. After travelling about 40 metres in this manner the glider was seen to climb steeply, to about 15 feet above the strip, then roll to the left before impacting the ground nose first. An inspection of the glider did not reveal any faults that were likely to have contributed to the accident. It is probable that the pilot was slow to react to the loss of directional control following the wing drop, and delayed in releasing the tow rope. The pilot of the tug aircraft stated that shortly after his aircraft became airborne he felt it being pulled to the left of the strip. He immediately released the tow rope. There was long grass along the side of the strip and it is likely that once the wingtip entered this, the task of attempting to regain directional control was made more difficult for the glider pilot.

Circumstances:

The aircraft was approaching to land into a 15-knot wind, with a slight crosswind component from the left. At about 60 feet above ground, the wind suddenly dropped completely, probably due to terrain and buildings. As the pilot yawed the nose of the aircraft to the right to line up with the strip the right wing stalled. The aircraft entered an incipient spin and impacted the ground nose first, approximately 100 metres to the right of the strip.

Circumstances:

During take-off, the pilot inadvertently allowed the engine/rotor rpm to decay. By the time he realised his predicament, the main rotor was overpitched and the helicopter slowly settled back towards the ground. With a loss of tail rotor thrust due to the overpitching, the pilot was unable to avoid the body of the helicopter rotating through 270 degrees. During the rotation, the tail rotor and main rotor struck a small tree. The helicopter landed heavily, spreading the landing gear skids.

During a low-level photographic flight, the pilot made a shallow left turn at about 400 ft agl and a low forward speed. When he increased the rate of turn, the helicopter began a rapid turn to the right and the nose pitched up. The rotation continued for 3 to 4 turns during which the nose pitched up and down. The pilot had almost regained control when the helicopter struck the ground heavily on its skids and rolled onto its right side. The cause of the accident could not be conclusively determined but no mechanical defects were detected. The most probable cause was the operation of the helicopter in a mode that induced tail rotor stall and at a height that precluded a safe recovery following loss of control.

Circumstances:

The pilot flew from Berwick to Bendigo as part of his solo navigation training. After resting on the ground for about an hour he decided to carry out circuit training before continuing the navigation exercise. Conditions were turbulent with a southerly wind of about 30 knots. On the first circuit, the aircraft made a normal approach for runway 17 with no apparent drift. However, during the landing flare the pilot experienced a change in wind speed and direction. The aircraft rolled right and drifted to the right side of the sealed runway. The pilot's attempt to correct the situation was unsuccessful and the aircraft landed heavily on the right wheel. The pilot applied full power for a go around, but the aircraft veered further right, and the right landing gear broke off.

Circumstances:

During a landing attempt, the pilot lost directional control of the aircraft. The aircraft entered foliage at the side of the strip.