Circumstances:

The pilot had been spreading Graslan, a herbicide, about five kilometres from an agricultural airstrip. The aircraft was being flown back to the strip at about 300 feet above ground level when suddenly, the engine developed a severe vibration. The pilot diagnosed a propeller blade failure and shut the engine down before it shook itself out of its mounts. The pilot chose the clearest area available for the forced landing, a sloping paddock covered in windrows consisting of recently bulldozed trees. The aircraft encountered one such heap of timber during its 60-metre ground roll. Post flight inspection found a 21-centimetre tip missing off one of the two propeller blades. Specialist metallurgical examination of the fracture surface indicated that the loss of the propeller tip was due to metal fatigue. The fatigue failure was initiated from an improperly blended mark caused by previous foreign object damage.

Significant Factors:

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

1. Fatigue fracture of propeller blade.

2. Improper maintenance by maintenance personnel.

3. Forced landing on unsuitable terrain.

About ten minutes into the helimustering flight, the engine stopped with a loud bang. A downwind autorotational approach from a low altitude was attempted. The pilot used most of the rotor's energy in stretching the glide to a small, natural clearing. The helicopter then fell from tree top height (about 30 feet) onto rocky, sloping ground. It rolled over and slid several metres down the 14 degree slope. The No 1 connecting rod had failed and breached the engine crankcase. The connecting rod had failed from fatigue initiated overload. The fatigue was initiated from a galling spot on the inside of the big-end which occurred as a result of the relaxation of the bearing nip. It is probable that the relaxation of the bearing nip was caused by repeated engine overspeeds.

Circumstances:

About twelve minutes after departure and while cruising at 1200 feet above the ground the engine speed reduced from 5200 to 2000 rpm. This was accompanied by a mechanical knocking noise and severe vibration. The pilot immediately shut down the engine down to prevent possible damage. He carried out an emergency landing into the most favourable area within gliding distance. On touchdown the aircraft decelerated rapidly nosed over and came to rest inverted. It was not apparent from the air that the grass in the paddock was about half a metre high. The crankshaft had fractured at the centre pin between the bearing and the helical gear. The fracture was caused by fatigue attributed to extensive cracking. It was not possible to determine if the cracking had been present since manufacture or initiated from a propeller strike event some 60 hours prior to the failure when the engine was installed in a different aircraft. No logbooks are required for this type of engine hence the complete history of the engine could not be determined. This accident was not the subject of an on-scene investigation.

Significant Factors:

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

1. Engine crankshaft failed due to fatigue.

2. Long vegetation in emergency landing field.

Recommendations:

It is recommended that the Civil Aviation Authority consider a requirement for airframe and engine logbooks for this category of aircraft particularly those with the potential for commercial operations such as flying training.

The purpose of the flight was to convey the three passengers to Casino for business. Prior to departing Scone the pilot telephoned Sydney Operational Control Centre Briefing Office and submitted a flight plan which indicated that the flight would be conducted in accordance with Visual Flight Rules (VFR) and proceed via Upper Bowman and Taree at 7000 feet above mean sea level (amsl) to Port Macquarie and then Casino.

The pilot also indicated when submitting the flight plan that no radio navigation aids were fitted to the aircraft. The pilot then received a briefing on the weather conditions that could be expected along the route to be flown. The winds were given as generally southerly at about twenty knots with the cloud as scattered stratus between 1000 and 2500 feet and areas of broken strato-cumulus between 2000 and 6000 feet amsl. At 0740 hours the pilot advised Sydney Flight Service (FS), by radio, that the aircraft had departed Scone at 0733 and was climbing to 7000 feet. At 0809 the pilot reported the aircraft's position at Upper Bowman, cruising at 7000 feet and estimating Taree at 0829. Twelve minutes later the pilot of another aircraft also bound for Taree contacted VH-UDX and asked the pilot to confirm the aircraft altitude as 7000 feet. The pilot of VH-UDX replied that his aircraft was at 6500 feet on descent to 5000 feet and that he had run into a bit of "murk". When questioned further by the other pilot and Sydney FS the pilot reported VH-UDX was at 6000 feet in cloud and requested the visibility at lower altitudes. The pilot was advised that the cloud base at Williamtown was 3000 feet and he then reported that he intended to back track to Scone. The pilot was then requested to activate the transponder fitted to the aircraft and VH-UDX was subsequently identified by radar 18 nautical miles south-west of Taree at 0828 hours. The pilot was advised of this position and reported his heading, which indicated the aircraft was tracking towards Scone. During the next few minutes Sydney FS obtained information from the pilot relating to fuel endurance; estimate for Scone; altitude and cloud conditions.

The last communication received from the aircraft was at 0838 when the pilot acknowledged an instruction to call Williamtown Approach (for radar assistance). Further communication attempts were unsuccessful. At about 0840, residents of Gloucester heard the sound of an aircraft engine, apparently at high power, moving from the west to the north of the town. They could not see the aircraft. At the time there was dense cloud overhead, base about 800 feet above ground level (elevation 350 feet amsl), with drizzle. The aircraft appeared suddenly, descending steeply from the base of the cloud. The nose rose momentarily then the left mainplane folded back against the fuselage, separated and dropped away. The empennage separated from the fuselage. The fuselage with the right wing attached struck the ground in a park on the western edge of the town. The left wing, empennage and some other debris landed several hundred metres to the north east of the main wreckage.

Subsequent investigation did not reveal any pre-existing fault with the aircraft that could have contributed to the accident. The weather conditions that were encountered by the pilot were substantially as forecast and relayed to the pilot during the pre-flight briefing.

Circumstances:

The pilot purchased the aircraft in kit form from the manufacturer when he was visiting the USA in June 1989. He completed a training course in the dual seat version comprising approximately 30 hours of dual instruction and was certified competent for solo flight on 10 June 1989. After returning to Australia, he assembled the aircraft with the assistance of an aircraft engineer and began flying it on 20 September 1989 and had flown approximately 5 hours since then. On the day of the accident, the pilot had been practising take-offs and landings at the Tully aerodrome, and after about an hour of flying stopped for a break and to check the fuel. During the break he said that he would fly for another half hour and then stop to refuel and have something to eat. During the next flight, the aircraft was seen proceeding along the runway and carrying out "S" turns to reverse direction. During the commencement of a turn to the right, whilst heading towards the southern end of the strip, the aircraft was seen to adopt a steep nose down attitude, and dive towards the ground. The aircraft impacted the ground inverted, adjacent to the strip on a heading of 200 degrees magnetic and travelled 15 metres after initial impact before coming to rest. There was no evidence to suggest that the aircraft was operating abnormally prior to the accident sequence, and no defects were found which may have contributed to the development of the accident. The aircraft pitched nose down suddenly, and the rotor blade struck the tailfin with considerable force before ground impact. The behaviour of the aircraft is consistent with that which may occur when a gyrocopter is subjected to zero or negative "g", causing normal inflight forces to become unbalanced, and the gyrocopter to become uncontrollable. The weight of the aircraft is removed from the rotor, and the engine thrust may then turn the aircraft upside down. This could be caused by levelling off from a climb too abruptly at a low forward speed and allowing the airflow through the rotor to be reversed.

Significant Factors:

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

1. The pilot was inexperienced and was teaching himself to fly the gyrocopter without the supervision of an instructor. His previous training was thorough, but its effectiveness was diminished by lack of continuity during the following 3 months.
2. The loss of control is considered to be due to misapplication of controls leading to a zero or negative "g" situation. The possibility of a wind gust or willy willy causing an upset was considered, but there was no such observation by witnesses, and the wind at the time of the accident was light and variable.
3. The longitudinal stability of the aircraft is dependent on the balance of forces, in the absence of a horizontal stabiliser. The aircraft was not fitted with a horizontal stabiliser which would have improved longitudinal stability and reduced control sensitivity.

Recommendations:

1. The Civil Aviation Authority should consider the introduction of two place gyroplanes for use in a training role. At the moment there is no avenue in Australia for such training and the number of accidents involving inexperienced pilots is significant. It is recommended that CAO 95.12 be amended to include dual place gyroplanes, and that a syllabus of training be specified similar to the FAR 61.85 requirements.
2. The Civil Aviation Authority should consider the establishment of a scheme, to assist the Australian Sport Rotorcraft Association to set up a training and checking system, which would be available to members in specified areas of each State where this activity is popular.

The pilot reported that an aerotow to 2700 feet agl seemed to be accomplished quickly. When the glider had descended to 1400 feet the pilot rejoined the circuit but then considered that the altimeter was defective. She believed that sufficient height remained to permit a landing at the strip and carried out a low, tight circuit. However, as the turn onto final was completed an immediate landing flare was required. A heavy touchdown occurred and the aircraft came to rest 175 metres after the strip boundary. Faulty alignment of the "thousands" needle in the altimeter had led to the pilot mis-setting the height of the strip prior to take-off. The indications she read from the instrument were therefore 1000 feet in error.

The pilot intended to drop a flour bomb at a local cricket ground. He subsequently advised that during the run-in to drop the bomb at 400 feet agl a downdraft was encountered. Full power was rapidly applied but the engine faltered and the aircraft collided with the top of a tree at a height of about 35 feet agl. Some 40 people were gathered under this tree at the time. The impact shattered the windscreen and the cockpit was filled with debris, and a 2 metre limb remained attached to the horizontal stabiliser. The pilot was able to retain control of the aircraft and a safe landing was carried out at the destination aerodrome. No evidence was found to support the pilot's claim that the aircraft was affected by a downdraft. It was possible that the pilot was distracted by the actions required to drop the flour bomb, and did not pay sufficient attention to the area ahead of the aircraft.

The pilot intended to land the glider as close as possible to the hangar. On final, speed was increased to make good the touchdown point, then the aircraft was held in level flight at about 20 feet above the strip. As the landing gear was selected down, the nose dropped and the glider impacted the runway heavily. The landing gear failed and the glider slid for 47 metres on its lower fuselage before coming to rest. The elevator trim had been set nose down for high speed flight, and although a trim check is required, it was omitted from the pre-landing checks. The pilot said that when he changed hands to lower the gear, he may have relaxed the pressure on the stick in his left hand which moved forward under the influence of the nose down trim, resulting the nose drop and the subsequent heavy landing.

The owner pilot had recently recovered his aircraft with new fabric, and is reported to have taxied it up and down the strip for approximately one hour before taking off. About 15 minutes after the aircraft became airborne, a witness reported that he heard a loud bang, followed by the engine noise stopping, and then observed the aircraft spiralling toward the ground from an estimated height of 600 feet. The aircraft impacted in an inverted attitude in a creek. The investigation revealed that the propeller had fractured in flight. It is considered likely, that due to the severe vibrations associated with the loss of part of the propeller blade, the pilot would have shut the engine down. The reason for the propeller failure could not be positively established. A modification to the engine installation had raised the aircraft thrust line and the pilot had carried out a number of additional modifications which moved the centre of gravity rearwards. It is considered probable that when the engine was shut down, a rapid pitch up occurred. Before the pilot could regain control, the aircraft stalled and fell into a spiral dive, from which there was insufficient height to recover.

During a cross country flight the glider encountered an area of sink. The pilot was unable to find any updraughts and selected a paddock in which to land. As the glider was on short final, it suddenly lost height and collided with the boundary fence of the paddock. The pilot was inexperienced on type and also lacked recent experience of outlandings. The paddock selected gave a shorter landing distance than desirable and the pilot aimed for a lower than normal height to cross the boundary fence. When sudden sink was encountered in the hot, turbulent conditions the pilot was unable to prevent colliding with the fence.