Collision with terrain

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.

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.

A passenger on board the aircraft, said that the measured length of the airstrip was 1,000 m, with trees on the left and open grasslands on the right. He said the airstrip surface was rough to the left of the centreline for almost the entire length. The airstrip also had a slight uphill gradient in the take-off direction.

The passenger stated that he had taken a short flight with the pilot earlier the same day. He said that during the accident take-off the aircraft was further to the left of the runway centreline than on the previous occasion, and it appeared to accelerate more slowly. At a height of about 100 to 120 ft above ground level, the stall warning horn sounded, and the aircraft began to descend towards the trees to the left of the strip. The left wing then clipped a tree, and the aircraft descended to impact the ground nose first.

The investigator was unable to obtain details of the accident from the pilot in command.

The pilot reported that the landing was being conducted directly towards the setting sun. This affected his ability to see the strip and the aircraft touched down on the clearway beside the strip proper. During the landing roll, the nose wheel entered a depression which crossed the clearway and collapsed. Damage was also caused to both propellers and the forward underside of the fuselage.

The pilot reported that he had made an approach to land on runway 32. During the landing roll the pilot became concerned that the aircraft would not stop before the end of the runway, and he decided to go around for another circuit. The pilot applied power and attempted to fly the aircraft off the ground at the end of the runway. The aircraft did not climb, and the right wing collided with a three metre high tree causing the aircraft to slew around and touch down again. The right wing, engine cowl and nosewheel were also damaged as the aircraft came to a stop, still on its landing gear and pointing in the opposite direction to the landing, approximately 70 m from the end of the strip.

It is probable that the pilot flew the aircraft off the ground at too low an airspeed and the combination of the low airspeed and its associated drag prevented the aircraft from climbing clear of the obstacles.

The student had completed six circuits as part of a pre-second-solo check. The student's performance was accessed as satisfactory, by his instructor, and he was cleared to complete four solo circuits.

On the first solo circuit the aircraft ballooned during the landing flare. The aircraft was then observed to descend rapidly and land heavily on the main wheels after which, the nose came down starting a porposing action. The student applied full power to go-around but pitched the nose up too high (the student reported that the stall waring light and horn came on). The aircraft rolled to the left and descended impacting the ground initially with the left wing. The aircraft pitched nose first into the ground pivoting on the collapsed nosewheel in a clockwise direction whilst skidding away from the runway and coming to rest, upright, and facing the opposite direction to landing.

It is probable that the student's inexperience led to control mishandling which resulted in a stall and loss of control close to the ground.

When the pilot arrived over Toowoomba Aerodrome, he noted that the windsock favoured runway 29 and that the wind was strong. During late final approach he inadvertently allowed the speed to reduce too far, and a bounced, heavy landing resulted. He applied full power to go around but a strong wind gust from the south (mainly crosswind) moved the aircraft sideways. The aircraft failed to achieve flying speed and struck the ground, left wing and nose low. When the aircraft came to rest, its three occupants left the cabin without assistance. They were not injured. A very experienced local pilot had landed some 20 minutes earlier and he said that he had nearly lost control in the gusting crosswind. The hangars are known to generate strong vortices over the eastern threshold in strong south-westerly wind conditions.

The pilot reported that just prior to taking off during a spreading operation, a line squall had passed over the strip. Soon after becoming airborne the aircraft encountered an area of turbulence with associated sink, which it could not outclimb. Although the pilot attempted to dump the load of fertiliser to improve climb performance, the aircraft struck the ground in a level attitude and collided with a water pump, tearing the nose landing gear leg from the aircraft.

It was later determined that the fertiliser was damp, which adversely affected the dump capability of the aircraft.

The pilot was completing an approach to runway 10 at the time of the accident. The wind was reported as blowing from 060 degrees at 10-15 kts. At a height of approximately 30 ft the aircraft was observed to roll and yaw to the left of the runway centreline. In what appeared to be an attempted correction by the pilot, the aircraft was observed to roll and yaw to the right. At a height of approximately 15 ft, it was observed to turn back to the left and track, in a nose high attitude and with decreasing airspeed, towards trees to the north of the runway. The aircraft collided with the trees and came to a stop in a nose-down position.

The pilot reported that the atmospheric conditions were turbulent, with a crosswind and some wind shear evident during the approach. He had decided to use only 20 degrees of flap for the landing because of the conditions. At approximately 30 ft the aircraft was affected by a sudden wind gust which caused it to turn left and away from the runway. He tried to correct and applied power to commence a go-around, but the aircraft continued to descend. He retracted the flap in an attempt to improve the aircraft's performance, but this aggravated the situation. He was unable to prevent the collision.

The aircraft departed Griffith for a chemical spraying operation in the Hillston area. A considerable amount of fog and low cloud was encountered enroute, however, the pilot said he had been assured by the farmer at Hillston that the area was clear.

Nearing Hillston the pilot was unable to find a break in the cloud cover, so he elected to track to the east to find an opening but was unsuccessful. Shortly after commencing a return to Griffith the pilot said, he found a large cloud break. He notified his base of his intentions and descended below the cloud base. After passing over a low range of hills he descended to about 300 feet above ground level to continue to remain clear of cloud, but shortly after he was unable to prevent the aircraft from entering lower cloud.

The pilot commenced a slow turn, still able to see the ground immediately below the aircraft. However, he was unable to outclimb rising terrain, despite attempting to dump the chemical load. The aircraft consequently struck the ground and was destroyed, however, the pilot was able to vacate the aircraft without injury.