The aircraft was engaged on agricultural operations in hilly country when it encountered a sink conditions.

Although the pilot applied full power and take-off flap, he was unable to prevent the aircraft from descending into trees tops on a ridgeline. The pilot dumped the load, but the aircraft continued to descend and impact the ground.

The pilot had not been aware of any sink indications during previous spray runs.

The pilot was tasked with spreading urea on rice crops.  With about 550 litres of fuel on board he accepted 1150 kg of urea for the first hopper load of the day.  The weather conditions included light and variable wind, less than five knots.  The outside temperature was about 14 degrees Celsius.  He took off to the north from a 700 metre, level, dry, dirt airstrip.  It was his first take-off from this airstrip in this type of turbine powered aircraft.  Prior to the take-off, he was aware that his employer had taken off from the same airstrip with an equivalent load in the same type of aircraft in similar weather conditions in the past.

Well into the take-off roll the pilot assessed that the far bank of an irrigation channel, just beyond the end of the strip, might be a danger so he activated the dump lever.  Very little of the load managed to exit the hopper because solids, like urea, dump very slowly in contrast to liquids.  Soon after the aircraft became airborne the left main landing wheel clipped the one metre high bank.  Beyond the channel was about 600 metres of obstruction free flat paddock.

Suspecting that the landing gear may have suffered damage, the pilot overflew the loader who advised that the left landing gear leg was trailing.  The pilot then elected to fly back to Jerilderie where another slow overfly confirmed the damaged landing gear.  On final he shut down the engine hoping to save it from unnecessary damage.  The aircraft undershot the runway and came to rest in an oat crop about 100 metres short of the threshold.

Had the pilot loaded the aircraft only to 3042 kg, in accordance with the approved flight manual recommended agricultural gross weight for take-off, the hopper would have contained about 150 kg of urea while flying with 550 litres of fuel on board.  This being a highly uneconomical hopper load, the pilot elected to carry 1150 kg because in accordance with the flight manual, operation of the aircraft at a gross weight in excess of the recommended agricultural gross weight for take-off is allowed at the discretion and on the responsibility of the pilot. Subsequent to the accident the pilot's employer again successfully took off from the 700-metre airstrip with 550 litres of fuel on board and 1150 kg of urea in the hopper in similar weather conditions.

The pilot advised that he commenced the take-off from the threshold.  His technique was to progressively increase power to 55 pounds of torque during the initial take-off roll.  Fifty five pounds of torque applies to a reduced take-off power technique favoured by operators in an attempt to save engine wear and tear.  Maximum take-off power is 58.4 pounds of torque which the pilot applied when concerned about the approaching channel bank.

No fault with the aircraft has been found which may have contributed to the accident.  The pilot advised that this aircraft performed as well as others of the same type which he had flown.

The consensus of opinion from other experienced agricultural pilots is that the aircraft was capable of taking off with the 1150 kg.  They believe it possible that the pilot may have applied the reduced take-off power a little too slowly, thereby accelerating too slowly during the initial portion of the take-off roll.  Also, when concerned about the embankment, he may have pulled back on the control column too early and may have inadvertently placed the aircraft nose high in a condition of higher than desirable drag at an airspeed too slow for rotation.  It is also possible that the aircraft encountered a light tailwind during the take-off roll.

Significant Factors

The following factor is considered relevant to the development of the accident:

1.   The take-off technique applied by the pilot was not optimum for the combined factors of aircraft gross weight, weather conditions, and airstrip length with an obstacle at the end of the strip.

A Boeing B737 was operating a scheduled flight from Darwin to Brisbane via route A464. The aircraft passed overhead Tindal at 1455, maintaining FL330, estimating the ATEGA waypoint (150 NM north-west of Mount Isa) at 1549. The aircraft was subsequently transferred from Brisbane ATC Sector 11K jurisdiction to Brisbane Sector 11 at 1515. Opposite direction traffic on A464 was a Boeing B747, operating a scheduled flight from Brisbane to Singapore. The aircraft passed overhead Mount Isa at 1430, maintaining FL310, estimating Tindal at 1613, and requesting a flight planned climb to FL350. The aircraft subsequently contacted Brisbane Sector 11 at ATEGA at 1525.

The Sector 11 controller had calculated an estimated time of passing of 1538 for both aircraft and correctly notated both flight progress strips. The B747 was co-ordinated to Sector 11K with the current and planned cruising levels. However, at about 1528, Sector 11 cleared the B747 to climb to FL350. At 1535, the B747 reported maintaining FL350 but one minute later queried opposite direction traffic below. The Sector 11 controller immediately recognised that the prescribed separation standards had not been provided and the B747 had climbed through the level of the B737 about five minutes, or 80 NM, prior to the time of passing.

A subsequent investigation found that the Sector 11 controller had been distracted by resolving a potential separation problem between two other aircraft within his area of responsibility. In addition, he had erroneously judged that all southbound traffic was below the B747, prior to issuing the climb clearance, although the relevant flight progress information available to him did not support this perception. A final opportunity to prevent the occurrence was lost when the crew of the B737 had apparently not recognised that the B747 had been cleared to climb through their level without adequate separation. The B737 had been on the same frequency as the B747 for some 10 mins prior to ATEGA.

Soon after lifting off, the helicopter yawed suddenly to the right. There was no response to rudder inputs by the pilot, but he was able to hold the helicopter in a level attitude as it descended to the ground. The main rotor blades came into contact with the boom and both skids were bent during the ground impact. The pilot was able to safely exit the aircraft. Later examination found that the rear most section of the tail rotor drive shaft had disconnected at the tail rotor gearbox input.

The helicopter crashed during mustering operations and was found on the edge of a lake by a ground mustering party. The pilot received head injuries and has no recollection of the event. Ground witness marks indicate that the helicopter was travelling rearwards when the right skid dug into the ground. This upset the helicopter and caused the rotor blades to strike the ground.

The pilot reported that the helicopter was being flown at 30 kt, 70 to 100 ft AGL, when the engine suddenly stopped. The helicopter struck trees and landed heavily during the subsequent emergency landing. Inspection of the engine by an engineer found no signs of an engine failure.

The pilot reported that, prior to take-off, the windsock indicated nil wind. He advised that the take-off roll appeared normal and that the aircraft had became airborne at approximately 50 kts. After lifting off, at a height "well above" the windsock, the aircraft suddenly appeared to lose airspeed. The aircraft then descended to contact the ground nose first and bounced again before coming to rest on the western side of the runway. The total distance from commencement of the take-off roll to where the aircraft came to rest was approximately 900 metres.

Both the pilot and passenger were able to exit the aircraft safely.

Witnesses working near the runway advise the aircraft may have been effected by a gust of wind that passed through at the time.

The warning light for the primary electrical inverter illuminated and then re-activated after the stand-by inverter was selected. The pilot decided to return to Mt Isa. A short time later all flight instrument "fail flags" indicated and sparks were observed near the top of the pilot's instrument panel. The avionics master switch was selected off and the aircraft later landed safely.

Later examination found that a section of electrical wiring under the instrument panel had "shorted" and burnt. Both inverters were unserviceable and the 115-volt main fuse was blown. It was determined that the electrical fault was probably initiated by the electrical wiring chaffing and then shorting out.

The student pilot was on his second solo training flight, having completed a one-hour dual training flight immediately beforehand. He reported that on his last landing, which he considered to have been possibly a little heavy, he had heard a crunching noise from the nose gear. Realising that the nose gear was damaged, he tried to keep the nose up as the aircraft decelerated, hoping to minimise damage to the propeller. However, as the aircraft slowed, the nose dropped, and the propeller struck the runway.

Inspection of the failed nose gear revealed it had failed as a result of the previous heavy landing.

The glider released from the tug at about 500 ft and flew a modified circuit, turning on to final approach at about 150 ft. The pilot attempted to deploy the spoilers but operated the cable release lever by mistake. This resulted in the aircraft overshooting the intended landing point. The pilot continued with the landing. At the completion of the landing roll, as the aircraft was turned off the strip, it collided with a termite mound.