After completing a dual instruction period of crosswind take-offs and landings the pilot prepared for solo exercises in the training area. At about 45 knots during the take-off roll the aircraft unexpectedly became airborne. The pilot had been correcting for the left crosswind and when the aircraft touched down again its heading altered sharply to the left. Attempts to regain control were unsuccessful and the pilot abandoned the take-off. Damage to the nosegear was sustained when the aircraft entered a ditch before coming to rest off the side of the strip. The wind at the time of the attempted take-off was gusting close to the crosswind limit for the aircraft type. After the aircraft ran off the strip, soft wet ground reduced braking effectiveness, and the pilot was unable to prevent the entry into the ditch.

The pilot reported that as full power was applied on the take-off run, he heard a loud bang and the aircraft yawed to the right. He shut down the right engine and brought the aircraft to a stop. Initial inspection revealed that the right propeller assembly had failed at the hub. One blade had separated from the hub and struck the nose section of the aircraft. It was determined that the hub had failed from fatigue which had originated at the root of the blade retention thread. It was estimated that the fatigue crack had propagated over about 900 engine start cycles, and had occurred at some time after a regular inspection to check for this type of cracking.

After conducting general flying for about 45 minutes the occupants returned to conduct circuit practice. During take-off after the third stop-and-go landing, an engine power loss occurred. The pilot lowered the nose of the aircraft rapidly but was unable to prevent a collision with the ground and a barbed wire fence. No positive cause for the engine failure was established, however the method of restraining the fuel lines to the aircraft structure was not in accordance with normal engineering practice, and could have restricted fuel flow to the engine. The pilot involved in this accident adhered to a directive issued by the industrial organisation of which he is a member and did not provide any information to assist in the investigation.

The pilot, who was an experienced glider pilot and instructor, was taking part in a gliding competition. Only 2 of the 12 competitors were able to complete the exercise, the remainder being required to outland. Almost 4 hours after being launched, the aircraft was sighted in a right hand circling descent, apparently being manoeuvred for an outlanding. At low level, the angle of bank was seen to suddenly increase and the nose dropped. The right wing struck the ground and the aircraft cartwheeled before coming to rest about 34 metres from the point of initial impact. It was evident that the aircraft had entered an incipient spin at too low a height above the ground to enable the pilot to recover control of the aircraft. The reason for the loss of control could not be determined.

During the course of the flight the pilot learned that the passenger in the right hand front seat held an American pilot licence and was experienced on the type. He allowed the passenger to manipulate the controls until the aircraft was on final approach and allowed him to keep his hands lightly on the controls during the flare and touchdown. During the landing roll the passenger, unnoticed by the pilot, inadvertently selected the landing gear up. The aircraft slid to a halt with the gear partially retracted.

During the initial climb of an aerotow launch, the glider experienced strong sink. The pilot released from the tow, but the sink persisted. The pilot attempted to return to the aerodrome, and continued with this attempt beyond the point where a safe outlanding could be made. A straight-in approach was made to a paddock, where shortly after touchdown the aircraft collided with a ditch and a fence.

The pilot was attempting to complete a solo flight of at least one hour duration as part of the qualification for the issue of a C Gliding Certificate. Witnesses reported that during the winch launch, the glider lifted off too early, and then assumed the climb attitude before sufficient airspeed had been obtained. The pilot stated that she released from the winch cable when she became aware that the airspeed was too low. At about the same time the right wing dropped and the aircraft turned through about one and a half revolutions before impacting the ground with the right wingtip. The pilot had attempted to correct for the wing drop with aileron control inputs, which were ineffective at the low airspeed.

At a height of about 200 feet after take-off the right engine lost power. The pilot feathered the propeller and commenced a gentle left turn in order to return to the strip. He later advised that the aircraft began to sink towards some large trees and he was forced to increase the angle of bank in an effort to avoid them. Shortly afterwards the aircraft struck the ground heavily in an adjacent paddock about 1 kilometre from the strip. The engine failure was caused by jamming of accessory drive gearing as a result of the effects of excessive wear within a magneto. It was probable that a mandatory inspection of the magneto which fell due 84 flying hours before the accident, was not conducted. On take-off the aircraft weight exceeded the authorised limit, however following the engine failure the pilot was able to maintain straight and level flight. A cleared area of ground lay ahead and just to the left of the flight path but the pilot had considered the aircraft had sufficient performance capability to permit a return to the strip.

The pilot, who had only been in the area for four weeks, was carrying out a mail run from Mount Isa to Burketown, via Lorraine, Gregory Downs, Lawn Hill and Hell's Gate. Approaching Burketown the aircraft encountered a duststorm and the pilot became unsure of her position. After searching for some time without being able to find Burketown she flew north to the coast and located what she believed was the mouth of the Nicholson River. From there she intended to proceed to Escott Station, thence to Burketown. The Non Directional Beacon (NDB) at Burketown was unserviceable. The pilot tracked upriver until she saw a station alongside a road. She decided to land to fix her position. During the subsequent landing the left wheel of the aircraft entered a washaway on the road and the gear leg collapsed. It was determined that the pilot had misidentified the particular river. The temperature in the area was over 40 degrees Celsius and one of the passengers had been almost continually airsick since leaving Hell's Gate.

Circumstances:

Shortly after take-off, on the 33 degree Celsius day and close to the approved maximum weight, the right engine surged and lost power. The pilot completed his engine failure after take-off check list and looked for a landing site. The only suitable area, in the aircraft's flight path was the harbour. The aircraft was unable to maintain height and the pilot reported that it descended at 100 feet per minute until it struck the water. The pilot then retarded the left throttle and allowed the aircraft to ditch. The symptoms reported by the pilot indicated that there had been an interruption to the fuel flow to the right engine. The investigation found that the right hand electrical fuel boost pump was unserviceable. No other faults were found. The reason for the engine failure could not be determined. At the manufacturer's approved maximum weight of 3060 kilograms the single engine performance charts contained in the USA approved Flight Manual, indicate that the aircraft should climb at 230 feet per minute at 33 degrees Celsius. The Civil Aviation Authority had approved an increase in maximum weight to 3357 kilograms, however, the Australian approved Aircraft Flight Manual does not contain any single engine performance information. The USA manual does not contain any information on performance at the increased maximum weight. Practical experience indicates that a single engine AC500S should be able to achieve a positive, but minimal, rate of climb at the accident flight weight and temperature, if all other conditions are at their optimum. On this occasion wind conditions were turbulent, making accurate flying difficult and the aircraft was not able to achieve a positive rate of climb once the right engine had failed.

Significant Factors:

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

1. There was an interruption to fuel flow to the right hand engine. It could not be determined whether the unserviceable electrical fuel boost pump contributed to the interruption.

2. The right engine lost power during a critical phase of the take-off.

3. Experience indicates that single engine performance in the prevailing conditions would have been marginal.

4. The pilot had limited experience on the Rockwell Commander 500S, and this coupled with the weight and weather conditions may have resulted in the aircraft not being able to achieve safe single engine climb.