Loss of control

Circumstances:

The aircraft reportedly crashed on take-off tearing off the nose gear leg.

Circumstances:

The pilot had operated from the strip on previous occasions and had flown out of the field twice prior to the accident flight. He set 10 degrees of flap for a "short field" take-off into a 15-20 knot Easterly wind. Soon after the start of the take-off roll when the aircraft speed was about 35 knots a sudden change of wind direction to the North was experienced. Whilst trying to maintain runway heading, he over-corrected with right brake and rudder and the aircraft veered off the right side of the runway. The pilot promptly shut down the engine, but the aircraft entered a dry creek bed, and the nose gear was broken off. The aircraft came to rest 50 feet from a fence at the end of the runway.

The pilot, who had just purchased the aircraft, had little experience on tailwheel types although he had completed two hours of training the previous day. On the following morning he intended to further familiarise himself with the aircraft, by carrying out a number of circuits. During an attempted three-point landing the left wingtip struck the runway and directional control was lost. The aircraft veered off the runway and came to rest outside the flight strip. The landing on which the accident occurred was conducted in gusting crosswind conditions. The recent training received by the pilot did not include any instruction in crosswind landing techniques.

At the conclusion of the student's first training exercise the instructor positioned the helicopter in a hover at about 3 feet agl and allowed the student to use the controls. The aircraft was headed into the 25 knot gusty wind when sudden sink was experienced. The student instinctively applied full aft cyclic control and the heel of the right skid dug into the ground as the helicopter moved backwards. The aircraft rolled onto its right side, destroying the main rotor blades and distorting the cabin area. The instructor had allowed the student to attempt an operation beyond the level of his current ability and had been unable to recover control when the sink was experienced.

As the helicopter was brought to a 20 foot hover, it began to swing to the right. The pilot applied left pedal but the rate of turn continued to increase rapidly until the helicopter impacted the ground. The right skid broke off and the aircraft came to rest on its right hand side. Examination of the tail rotor pitch control system revealed that the bolt which connects the tail rotor pitch control arm to the control rod, below the tail rotor gearbox, was missing. The bolt was never found and the reason for its absence could not be determined. It was evident that the loss of the bolt resulted in the loss of tail rotor control.

The pilot had built the single seat aircraft himself and had previously only flown it on one occasion. After completing the first circuit, the aircraft was taxied back to the threshold and the second take-off commenced. Just after lift-off the aircraft was observed to pitch nose up. The right wing dropped and the aircraft turned to the right before impacting the ground. When the aircraft tail came up during the take-off roll, the pilot became concerned that it was too high and that the propeller might strike the ground. In attempting to avoid this, excessive back pressure was applied to the control column. The aircraft became airborne prematurely and then stalled.

The aircraft was being flown between 500 and 1000 feet agl at 60 knots with 20 degree of flap. A mob of sheep was spotted and the pilot turned right to keep them in sight. The stall warning sounded and the pilot noticed a lack of elevator control but did not associate this with a stall. Descent continued while the pilot was engrossed in the elevator problem until the aircraft struck trees in its path. A major portion of the right wing was severed and the aircraft came to rest on its side.

The pilot was approaching to land at the conclusion of his second flight on the type. The approach was normal, however the glider floated the length of the strip at a height of about 25 feet. At the end of the strip a turn was commenced but after completing about 90 degrees an incipient spin developed and the glider struck the ground. The pilot subsequently advised that he had activated the cruise flap lever instead of the air brake. The two levers are located side by side in the cockpit. It is likely that the pilot was suffering a degree of heat stress. He had been in the cockpit, exposed to the sun for two and a half hours and he had not eaten since breakfast. He reported that during the final stages of flight his reactions were affected by fatigue and the heat.

The helicopter was being operated in clear conditions, with a five knot South - Westerly breeze, and an outside air temperature of minus six degrees Celsius. After landing on a snow covered ridge, the passengers advised that they would require only a short period of time to complete their work. While waiting, the pilot maintained sufficient power to prevent the helicopter sinking deeper into the snow than approximately 45 centimetres. On DEPARTURE, the helicopter lifted normally clear of the snow into the hover, then turned approximately 45 degrees to the left, to follow the ridge line instead of flying direct across the valley to the next destination. During take-off, slight sink was encountered. This was controlled by an increase in collective pitch, but almost immediately further sink occurred. The pilot again increased collective pitch and forward cyclic control expecting to accelerate through the sink. The skids contacted the snow surface, with the right hand skid digging in deeper, causing the helicopter to roll to the right. In response, left cyclic control and full collective were applied , but the helicopter continued rolling to the right, allowing the main rotor blades to contact the snow, which caused the helicopter to overturn. The prevailing conditions would appear to preclude the possibility of power failure caused by snow ingested through the engine air intake. A full mechanical inspection was made of the helicopter and its engine, but no fault was detected. It is possible the aircraft was over-rotated, allowing the skid toes to contact the snow. The cause of this accident was not determined.

On final for runway 16 the pilot noticed another aircraft on departure using runway 34. The climbing aircraft turned right immediately to allow sufficient clearance for the landing aircraft to continue its approach, however, the pilot elected to go around instead. During the go around the aircraft mushed onto the flight strip, broke off its nosewheel, nosed over and came to rest inverted 30 metres from the initial impact point. The aircraft entered the circuit without making inbound or circuit entry calls and because the wind was still directly across the strip, the pilot decided to use runway 16 which he had used for the take-off. Two aircraft already in the circuit, but using runway 34, were not sighted until a head-on condition had developed with one of them. During the go around, with the speed at about 65 knots, the flaps were fully retracted. Prior to this departure a dual check was completed as the pilot had not flown the Cessna 172 for 8 years.