The student helicopter pilot was conducting his second solo flight at Hoxton Park. The weather was fine, with almost no wind. Prior to commencing the solo phase, the student had completed a satisfactory dual circuit check.

As the instructor walked away from the helicopter, he heard a "thump'. As he turned around, he saw the helicopter had rolled onto its side, causing substantial damage to the rotor blades. The accident was consistent with 'dynamic rollover'. The student was not injured and was able to exit the helicopter.

As the student had commenced to lift off the helicopter had rapidly rolled to the right. Although he had expected there would be some rolling tendency, the rate of roll was greater than the student had anticipated, and he had been unable to prevent the rollover.

The aircraft had been parked in a recently opened grass parking bay. Whilst the aircraft was taxiing from the parking area onto a taxiway, the aircraft's left main landing gear wheel sank in soft sand on an unmarked irrigation outlet. The metal plate covering the outlet was not supported on one side. The wheel ran onto the unsupported side of the plate, causing it to flick up and puncture the underside of the wing and fuel tank. Exit routes from the parking area were not marked and the path taken by the pilot was not normally used.

Local Safety Action

The airport authorities are intending to clearly mark parking area entry and exit routes.

The pilot reported that when he was about 3 NM from the departure point he smelt smoke, and then saw smoke entering the cabin and trailing behind the aircraft. He immediately turned back towards a suitable landing site about 1 NM away, but the engine lost oil pressure and performance started to deteriorate. The pilot carried out an autorotational landing with partial power into a confined area, and on touchdown the vertical stabiliser and tail rotor blades struck an anthill. Subsequent inspection revealed a ruptured oil line as the cause of the smoke and loss of oil pressure. Structural damage was confined to the tail rotor blades, horizontal and vertical stabilisers, tail rotor transmission and drive shaft, and tail boom.

The pilot reported that while he was conducting a turn above some cattle, the aircraft appeared to lose speed and altitude. The aircraft was about 75-100 ft AGL at the time. The pilot pushed the control column forward and applied full power. However, this had little effect, and it became obvious that the aircraft was going to strike the ground. The pilot said that just before impact, he pulled back on the control column. The pilot could not recall looking at the airspeed indicator during the final stages of the flight, and did not recall hearing the stall warning sound. However, he considered it likely that the aircraft stalled during the turn and that there was insufficient height above the ground for him to effect recovery to normal flight.

The helicopter departed Mount Green in a northerly direction at approximately 1755 CST, for a survey of the locations of Army personnel in the area who were manning Rapier missile sites. The pilot said that while approaching one of the sites, he descended to approximately 100 ft AGL, and commenced a left-hand orbit while his passenger, an Army officer, was explaining the layout. When he was about halfway through the turn and maintaining approximately 60 knots with about 30 degrees angle of bank, the nose suddenly yawed to the left, and the helicopter descended rapidly in a nose low attitude. The helicopter impacted the ground, and slid backwards into a thicket of small trees 2 to 3 metres high.

One main rotor blade had sustained a spar fracture approximately 14 cms from the blade tip. Blade weight segments were installed in this region and could not be found after the accident. A section of the blade skin and honeycomb core extending over a distance of approximately 34 cms from the blade tip had also been lost. The nature of damage displayed by the blade was consistent with an impact between the blade leading edge and a solid rocky object, at a point approximately 20-25 cms from the blade tip, while the blade was rotating.

A series of unusual paint transfer markings along the upper surface of the leading edge of one main rotor blade was noted during examination. The paint was dark green in colour. Abrasive scores through some of these markings indicated that paint transfer associated with contact with some other material or component occurred prior to collision with the ground. It was established that the blade had struck a ground-to-air missile casing which was painted dark green. The stage in the accident sequence at which this occurred could not be determined.

The owner pilot was conducting a private flight from Coober Pedy to Parafield, to have a 50 hourly inspection conducted on his aircraft. He was accompanied on the flight by his wife and three children aged under nine.

The pilot was making an approach to land on runway 26 right at Parafield in strong gusty wind conditions. During the flare prior to touch down, the aircraft "ballooned". The pilot applied power to recover the situation, however, the right wing dropped. The pilot estimated the bank angle reached approximately 70 degrees. The pilot recovered the wing drop with rudder and aileron only to have the left wing descend quickly. Power was again applied to cushion the ground contact, however, the right-wing tip touch the ground and dragged for approximately 90 m. The pilot attempted to recover the dropped wing, but the aircraft ground looped, departed the runway and came to rest in a drainage ditch north of the flight strip. The pilot and passengers evacuated the aircraft without injury.

The pilot was conducting circuits on runway 30 in conditions of strong northwesterly winds gusting to 25 knots. During the approach the pilot elected to keep the engine RPM higher than normal to counter the strong winds. During the final stages of the approach to landing, the rate of descent increased significantly, and the aircraft experienced some mechanical turbulence. While the pilot concentrated on keeping the wings level, the nose of the aircraft dropped, and the aircraft landed heavily on the runway. The nose wheel strut failed, the propeller contacted the ground, and the aircraft skidded to a stop on the runway having sustained substantial damage. The pilot then evacuated the aircraft.

The pilot later stated that he was concentrating on the landing and did not consider going around. Skid marks on the runway indicated that the aircraft touched down with some sideways drift which would have put side loads on the landing gear.

A significant factor in this accident is the pilot's continuation of the landing in conditions which exceeded his ability.

The pilot reported that the strip had received heavy rain during the previous week and that only 680 m of the 1,000 m length was usable for operations. The centre of the strip was dry, but the edges were soft with water standing in the table drains at the side. The pilot said that the take-off run was normal until lift off when the aircraft lost 15 kts of airspeed as the right main wheel ran through a soft patch.

As result, the climb out was slow and shallow, and the aircraft veered to the right of the strip. The pilot was unable to avoid trees about 100 m to the right of the strip. The left wing struck foliage, but the pilot was able to keep the aircraft airborne. After landing the aircraft to assess the damage, the pilot found that the leading edge of the left wing was damaged.

The Cessna 337A (C 337A) was being used to conduct the final endorsement training flight of a company pilot. The instructor reported that he did not conduct a formal pre-flight brief with the student. He had presumed the student had adequate knowledge of the aircraft systems, although the student was not subject to a written systems examination and the instructor did not orally check the extent of the student's systems knowledge.

The student's previous training flight had been with another pilot in a G model of the Cessna 337, which used an electrical mechanism for raising and lowering the landing gear, whereas the C 337A used a hydraulic pump driven by the front engine to power the landing gear mechanism. The instructor's previous flight was also in the Cessna 337G.

During the third circuit of the endorsement flight, the instructor simulated a front engine failure by leaning the mixture of that engine. The instructor reported that he talked through and assisted with the engine shutdown checks as the student had limited multi-engine experience and was slow in responding to the simulated failure. The instructor also reported that he retarded the front engine's throttle following the engine shutdown but did not recall hearing the gear warning horn. The gear warning horn is normally actuated when either throttle is retarded below a point approximating 13 inches of manifold pressure while the landing gear is not down and locked. Landing gear extension had been intentionally omitted from the downwind pre-landing checks as the pilots had intended to lower the landing gear when the aircraft was settled on the correct final approach path. With the front engine shutdown, there was no hydraulic power available to lower the landing gear, so when the student selected the landing gear down during the final approach, it did not move. Neither pilot noticed the lack of a safe indication and neither looked outside to visually check the landing gear position.

Although neither pilot recalled hearing the horn sound, even during rear engine throttle retardation in the landing flare, the horn was later found to be operational. However, during a subsequent flight, it was discovered that the gear warning horn operated intermittently and that a microswitch required replacement.

Finals checks, including the checking of the landing gear position, were reported by the instructor as not being conducted due to the high workload during the final approach.

The pilots did not realise that the landing gear was not down until the belly-mounted cargo-pod hit the ground during the landing flare. The aircraft maintained a level attitude during the landing retardation whilst the instructor shut-down the rear engine. As the aircraft came to a stop, it rocked back on to the tail and the rear engine propeller struck stones at low RPM. The pilots then vacated the aircraft without further incident.

The instructor knew the student pilot both at work and socially, which probably influenced him to approach the training in an informal manner. Because both pilots had conducted their previous flying in a different model of the Cessna 337, the lack of formal pre-flight and systems briefings probably contributed to the accident.

Local Safety Action

The company has undertaken to introduce formal briefing requirements for all training programs and a training syllabus. An amendment to the theory examination on the Cessna 337, which is used by the company for endorsement purposes, has been incorporated. This amendment reflects the different landing gear operating requirements of the Cessna 337G and the Cessna 337A. As the two models are available to company pilots, the A model landing gear hydraulic requirements are to be placarded as a measure to reduce any future confusion.

The pilot of the C188 aircraft was carrying out spraying operations 12 km West of Clare. Due to his low experience level on the C188, the pilot was operating with a reduced internal chemical load of 600 litres rather than the maximum 757 litres. The pilot advised that on entry to a procedure turn at the completion of the fourth spray run he encountered excessive sink due to a tailwind.

The pilot attempted to arrest the sink rate by dumping the remaining chemical load and applying full power, however, due to late manoeuvering to avoid power lines this proved unsuccessful, and the aircraft impacted the ground left wing low. The pilot vacated the aircraft having suffered minor injuries in the accident.