Because the external load could not be released electrically, the pilot landed on snow to allow an assistant to release the load manually. After the load was released, the assistant had moved to the pilot's window to discuss the next load when the rear of the left skid began to sink into the snow. The pilot attempted to correct the situation but the main rotor struck the ground and the aircraft rolled over. The helicopter was not fitted with any load spreading devices for operations in snow. Although the pilot had tested the load bearing capacity of the snow, the technique did not provide sufficient indication that the snow could not support the aircraft. An intermittent electrical malfunction is believed to have caused the cargo hook failure.

On commencing the clean up run, the wire deflector on the aircraft struck a single power line. The top section of both the fin and rudder were severed from the aircraft which was subsequently landed at the DEPARTURE strip without further damage. The pilot had been briefed on the crop to be sprayed and on the location of power lines in and around the paddock. After cleaning up the other edges, the final run was commenced with the aircraft flying parallel to the main power lines. The pilot temporarily forgot the presence of the single wire running from the main line into the paddock.

Circumstances:

The aircraft was being used to deliver newspapers. On arrival and during the landing roll, the pilot noted that the air strip surface was soft. A rain shower had passed over the air strip about an hour earlier. The initial part of the subsequent take-off roll appeared to be normal, but after using about half of the 950 metre strip the pilot became concerned that the aircraft had not reached flying speed. At an airspeed of about 60 knots the aircraft became airborne briefly, before settling back onto the strip. At that point, the pilot elected to abandon the take-off, closed the throttles and mixture controls, and applied full braking. The aircraft skidded for about 300 metres, coming to rest about 50 metres beyond the end of the strip. During the overrun the left main landing gear collapsed.

Circumstances:

The pilot departed on a positioning flight with the helicopter fuelled to capacity. While cruising at 2500 feet and 60 knots the pilot heard and felt a buzzing sensation which lasted for about 3 seconds. The helicopter then suddenly yawed rapidly to the right and the engine RPM increased by 150 RPM. The pilot reduced the throttle setting to idle and entered an autorotation at 55 to 60 knots. Power was applied at 1000 feet to check on controllability, but the helicopter again yawed rapidly to the right, so the pilot again entered autorotation. As the pilot commenced to flare the helicopter directional control was again lost, so the pilot made a run-on landing avoiding the largest tees in the process. However, the area is heavily timbered, and the main rotors struck several smaller trees, prior to and after touchdown. The investigation established that the failure was initiated by excessive wear of the inner track of bearing PN47-620-929-1. The wear caused an increase in the centre distance between the ring gear and the pinion gear. This resulted in increased loading and wear on the crowns of the teeth of the output drive shaft gear because the drive was being transmitted by the crowns rather than the full length of the teeth. Drive to the tail rotor was lost when the crowns of the teeth were worn away. Secondary damage to the bearing inner track removed all of the original surface layer. This prevented further examination to determine what initiated the wear. There was no suitable terrain available for the pilot to make a successful autorotational landing.

Significant Factors:

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

1. Excessive wear of bearing PN47-620-929-1. It could not be established what initiated the excessive wear.
2. The drive to the tail rotor was lost when the crowns of the gear teeth were worn away.
3. The terrain was unsuitable for a forced landing.

Passengers reported that after takeoff, there had been a high pitched noise and that a gap had appeared around the top edge of the forward cabin door. The pilot, who was wearing headphones, indicated that he did not hear the noise and was unaware of the gap at the top of the door. A female passenger was seated in the front right seat beside the pilot and adjacent to the door. She was partially resting against the door, watching the terrain below. Her lap harness was secured. Shortly after the pilot commenced descent from 7000 feet, there was a loud bang and the door opened. The events which accompanied, and immediately followed the door opening occurred quickly and could not be determined precisely. However, the female passenger claimed that the door opened 30-40 centimetres, that her right hand contacted the upper surface of the wing, and that her head and shoulders were outside the cockpit. Two articles of clothing she was holding were lost overboard. The male passenger seated directly behind the female passenger thought that the door had opened fully and that the passenger fell so that her upper body was partially outside the cockpit. The pilot reported that he thought the door had popped open only 10-15 centimetres. The male passenger said that he reached around the seat to assist the female passenger and that she then leaned away from the door and held on to the back of the pilot's seat. As the aircraft was slowed to 90 knots, he and the pilot attempted to close the door without success. The pilot then decided to land the aircraft at Maroochydore. The male passenger held the door until the aircraft landed. On a rriva l at M aroochy dor e, the pil ot operated t he door loc king mecha nism a num ber of times an d, as i t appeared t o be fu ncti oning nor mal ly, he ele ct ed to continue the flig ht. The ma le pass en ger offe red to take t he fem al e pas se nger's place in the front rig ht seat adja cen t to the doo r bu t the off er wa s declined. Soon aft er de part ing Maro ochy dor e on the shor t flig ht to Brisban e, a gap again appeared around the top of the door accompanied by wind noise. The female passenger held the door closed until the aircraft landed at Brisbane. The maintenance organization which rectified the fault reported that the upper lock was out of rigging such that it was not held over-centre sufficiently to allow for fuselage flexing in flight. The cable was adjusted and the aircraft returned to normal flight status. The effect on the sequence of events, if any, of the female passenger leaning against the door was not determined. The cause of the the female passenger's injuries was not established. This occurrence was not the subject of an on-site investigation.

The aircraft had been cleared via a Standard Instrument Departure which required the aircraft to turn at three miles by Distance Measuring Equipment (DME) onto a heading of 170 degrees and to reach 2500 feet or above by 5 DME. The aircraft was to maintain heading 170 degrees until 7 DME, then turn onto a heading of 065 degrees to intercept the departure track. However, the aircraft was observed to turn at 3.5 miles onto a north-easterly heading and track to intercept the departure track. This was the first time the Captain had flown out of Adelaide, however, he was familiar with Standard Instrument Departures, having flown similar procedures overseas. On this occasion the Captain was concerned that he complied with the minimum altitude requirement and concentrated on this aspect to the detriment of the rest of the procedure.

Circumstances:

During the take-off run, as power was being increased, the nose wheel broke through the runway surface and the nose gear leg collapsed. The central area of sections of the runway had previously been filled with coarse river gravel. This fill had then been overlaid with finer material and bonded with an oily fluid. When the aircraft broke through the top crust, the wheels sank readily into the gravel, and the nose leg was torn from the aircraft.

Significant Factors:

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

1. The runway surface was of inadequate strength for the operation.

2. Overload failure of nose gear mounting. This accident was not the subject of an on-scene investigation.

As the pilot lifted the helicopter into the hover he felt an unusual vibration and was unable to prevent an immediate turn to the left. Shortly afterwards the nose of the helicopter pitched up and down sharply and the tail rotor guard struck the ground two or three times. The guard broke and portions of the tail rotor blades were torn off. The helicopter then landed heavily, damaging the landing skid. Engineers found no significant fault with the helicopter. It is highly probable that the pilot took off with the hydraulic assist to the cyclic control inadvertently selected off. This helicopter has an electrical on/off hydraulic switch which is not common on the Bell 47-G2. The pilot was more familiar with the mechanical on/off system. He may have been distracted from completing his pre-take-off checks by explaining them to the passenger. With hydraulics selected off, feed back forces occur through the cyclic control; this could be felt as an unusual vibration. Because of the feed back forces, the pilot began to overcontrol the helicopter thereby causing him to channelize his attention to the cyclic control to the detriment of directional control. Although the pilot had been trained in "hydraulics off" emergency procedures in flight he had never before experienced lifting a helicopter into the hover with the hydraulics selected off.

Circumstances:

The solo student pilot was conducting left-hand circuits on runway 27 in a westerly wind of about 15 knots. When he transmitted his "base" call on VHF frequency 119.1, he neither heard nor saw another aircraft in the circuit. During the landing roll he realised he was on a collision course with a Piper PA28 which had landed on runway 36. He applied brakes and veered left while attempting to avoid a collision. At the runway intersection both aircraft missed each other by about one metre. After the near-miss the student applied full power for a go-around but his aircraft veered further left. As he attempted to steer back on to runway 27, the left side of the horizontal stabiliser struck the airfield boundary fence. The pilot of the Piper PA28 was conducting an Instrument Flight Rules flight via Avalon. The PA28 was equipped with only one VHF radio. The pilot said that while still in the Avalon control zone he called Geelong on 119.1 to advise his ETA. He said he was told the wind was westerly but could not recall being advised of traffic. He then returned to Avalon tower frequency. Geelong Airport personnel said the pilot was advised that the duty runway was runway 27 and that there was a Cessna 152 operating in the circuit. As 119.1 is not recorded it was not possible to check exactly what was said. Passing Avalon control zone boundary (approximately nine kilometres north of Geelong) the pilot selected the Melbourne area frequency 124.9 and remained on 124.9 for the arrival at Geelong. Flight Service advised of following traffic also destined for Geelong. The PA28 joined on downwind for a right circuit for runway 36. On the downwind leg, the pilot saw a Cessna to the left and about 400 feet below. He thought this aircraft was in transit whereas it was actually on the base leg for runway 27. He had no further sighting of the Cessna until established on the landing roll, at which time the PA28 passenger gave warning of a possible collision.

Recommendations:

It is recommended that the Civil Aviation Authority clarifies the practice of using 119.1, particularly at Authorised Landing Areas, and produces relevant documentation for pilots.

Circumstances:

The pilot had owned the gyrocopter for some time but had flown it infrequently due to engine tuning problems. On previous flights, the pilot had flown from a larger strip near Innisfail. Since then, he had enhanced the engine instrument cluster to better monitor the performance of the turbocharged engine. The pilot's intention was to test the new instrument installation at the smaller Deeral strip before proceeding to the larger strip for further flying practice. He had planned to make six runs along the 500 metre long strip without becoming airborne, with a 15-knot crosswind. On the fifth run, the witness noticed that full power was applied for much longer than on the previous runs. The aircraft accelerated to flying speed and became airborne. At a height of about six feet above the strip, the pilot appeared to experience some difficulty with the crosswind. The gyrocopter banked and yawed to the right, it then dived into the ground, and cartwheeled forward before coming to rest in a drain.

Significant Factors:

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

1. The pilot was inexperienced.

2. The wind conditions were unsuitable for the operation attempted by the pilot.

3. The pilot lost control of the aircraft due to crosswind and turbulence.

Recommendations:

In this accident the pilot may not have been injured as seriously if he had been using a harness which prevented him from sliding forward underneath and out of the harness. A five or six point harness with a crotch strap would have held the pilot in his seat where the surrounding structure would have offered more protection.

1. It is recommended that the Sport Rotorcraft Association of Australia should disseminate information to its members on the advantages of using seat belts with additional mounting points.