Collision with terrain

The pilot and passengers were overseas visitors taking part in an aerial safari. The flight apparently proceeded normally until a series of garbled radio transmissions were recorded from the aircraft, which then failed to reply to further calls. Despite an intensive search, the wreckage of the aircraft was not found for 2 months. It was evident that the aircraft had collided with trees at high speed while in a steep descending attitude. Examination of the wreckage did not reveal any pre-impact fault that could have contributed to the accident. A post analysis of the prevailing weather conditions indicated that areas of rain showers and low cloud existed over the higher terrain in the region. It is probable that the pilot lost control of the aircraft after inadvertently entering cloud.

Circumstances:

The pilot had been spraying rice fields when the aircraft began to vibrate severely and lose height. He began a turn into wind to position the aircraft for a forced landing in a dry paddock, adjacent to the field under treatment. During the turn the aircraft struck a small earth bank which tore off the main landing gear. The reason for the vibration has not yet been established. However, a piston failure is suspected as pieces of piston and piston ring material were found in the engine sump.

Circumstances:

The pilot had engaged in gliding activities for more than thirty years. These activities were interrupted in December 1987 when he underwent coronary by-pass surgery. On receipt of a medical clearance from his coronary specialist, the pilot resumed flying gliders in February 1989. He had since accumulated 31 flights of which 18 were solo. On the day of the accident, the pilot arrived at the airstrip at about 0930 hours and during the day assisted with glider launch and recovery operations. Late in the afternoon the pilot was authorised by the duty officer for a solo flight. After a winch launch in a northerly direction in light wind conditions, the glider was observed to perform several steep turns before positioning for a right hand downwind leg for a landing in a northerly direction. The pilot reported his position by radio on the downwind leg in accordance with the gliding club's standard procedures. The flight was witnessed by numerous club members who were generally located at the southern end of the airstrip. They reported the approach appeared normal until the glider was established on base leg. The turn onto the final approach was delayed such that the glider lined up on the western side of the strip which is reserved for winch launches. Soon after, when the glider was at an altitude of about 150 feet above ground level, it commenced a turn to the left. The glider levelled out on a south-westerly heading and then entered a climb, from which it apparently stalled, and dived from view behind trees. The wreckage was found in timbered country about one kilometre from the southern end of the gliding strip. The wreckage distribution suggested the glider had rolled inverted and dived near vertically into the ground. A technical examination revealed no evidence of any pre-existing fault or defect. The manoeuvres following the turn onto final approach were consistent with the pilot being incapacitated. The autopsy revealed the pilot had suffered a heart attack.

Significant Factors:

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

1. The pilot was incapacitated when he suffered a heart attack.

2. Loss of control in flight due to pilot incapacitation.

Following a 30 minute flight the pilot landed the balloon and the passengers waited in the basket for the retrieve vehicles to arrive to effect a passenger changeover. During this period a strong wind blew up, caught the balloon and dragged it towards trees. The pilot advised the passengers to adopt a crouch position and operated the burner to apply heat to raise the balloon. The balloon climbed steeply, cleared the trees then descended rapidly, bounced and the basket began oscillating about 30 degrees either side of vertical. The pilot was thrown out of the basket and 10 of the 11 passengers received injuries, although all remained in the basket. The balloon continued to be blown along the ground and one of the passengers climbed into the pilot's section of the basket and applied heat, this took the balloon aloft. The pilot chased the balloon and after one of the retrieve vehicles located him he was able to contact the balloon by radio and relay instructions on the use of the burner to the passenger. The balloon landed about 3.5 km from the position it had been waiting to changeover the passengers.

The owner of the aircraft is reported to have worn a neck brace to assist with his recovery from a neck injury suffered some years ago. On the evening preceding the accident he had complained of feeling unwell. The next morning he rose at about 0600 hours and apparently prepared the aircraft for a flight to a neighbour's property. The wreckage of the aircraft was located about four kilometres north of the pilot's homestead at 0830 hours. The aircraft was found to have impacted the ground in an inverted attitude. Examination of the wreckage indicated that the aircraft had been constructed and maintained to a high standard and no defect could be found that may have contributed to the occurrence. The aircraft was fitted with a serviceable emergency parachute which had not been activated by the pilot. The actuating lever was readily accessible within the cockpit. Post mortem examination revealed that the pilot suffered from coronary artery disease. It was also reported that he had previously suffered several periods of total incapacitation. It is considered possible that he may suffered incapacitation in flight.

The pilot was called out at about 0400 hours local time for an urgent medical flight from Wynyard to Melbourne. This required positioning the aircraft from its base at Devonport to Wynyard. The take-off from Devonport was made in darkness with an overcast sky and light drizzle. The aircraft then apparently continued on the take-off heading at high power and low level until it struck the ground at high speed in a forest area 25 km south of Wynyard and 56 km from Devonport. The cause of the accident could not be determined but the possibility of pilot incapacitation could not be discounted.

The aircraft had been chartered to transport a television film crew to Sydney, departing Armidale at 2130 hours. After rising about 0800 hours the pilot had spent the day working in his garden and watching television. At about 1600 hours he went to the airport to prepare the aircraft for the flight to Sydney and to submit a flight plan. He returned home at 1745 hours for a meal and planned to proceed to the airport at 2045 hours. Shortly afterwards he received a telephone call from another client requesting a charter flight to Sydney. He agreed to carry out the additional flight and DEPARTURE was made from Armidale at 1830 hours, with the return flight arriving from Sydney at 2130 hours. After landing the pilot refuelled the aircraft and waited at the airport for the film crew, who were delayed and finally arrived at about 2310 hours. The film crew requested that an additional passenger be flown to Sydney and after calculating the weight of the baggage the pilot agreed to the carriage of that passenger. The aircraft was loaded, with the front seat beside the pilot being occupied by Mr Phillips. The other three passengers were seated in the rear passenger area, one facing aft while the other two faced forward. All passengers fastened their seat belts, although Mr Phillips used only the lap portion of the lap/sash belt which was provided for the front seat passenger. After both engines were started, the aircraft was taxiied to the threshold of runway 23 where the engine checks were completed. The take-off run was commenced and a witness reported that the aircraft became airborne after a ground roll of about 1100 metres and then commenced a shallow climb.It then disappeared from sight. It was established the aircraft entered a descent and shortly afterwards it collided with a number trees in an apple orchard before impacting the ground about 1400 metres beyond the point where it became airborne. Subsequent investigation did not find any fault with the aircraft or its systems that would have contributed to the accident. At the time of the accident the wind was calm, the night was dark with no moon light. Once the aircraft passed the end of the runway no ground lights would have been visible to the pilot. These conditions may cause a pilot to experience sensory illusions; so he must rely solely on the flight instruments in order to establish and maintain correct aircraft attitude. Whether the pilot of VH-AWT was affected by such illusions on the particular occasion could not be positively determined. The pilot selected the initial climb attitude of the aircraft by referring to the runway lights. This technique is considered less than optimum, for the recommended technique requires reference to the flight instruments for attitude selection and maintenance. Reliance upon reference to runway lights during the initial climb may result in a lower than desired climb attitude where a runway slopes down in the direction of take-off. This condition exists on runway 23 at Armidale. ((1))

A group of pilots had travelled from a property strip to a nearby dam in order to complete training exercises on a float-equipped Bell 47 helicopter. VH-SRE was not fitted with floats but had been used to ferry some of the pilots to the area. At the conclusion of the training operation the pilot arranged to ferry VH-SRE back to the property strip. After take-off a practice autorotation was conducted over the dam and was followed by some unauthorised low flying in the vicinity. On arrival at the strip low level runs were performed along the strip with torque turns at each end. Control of the aircraft was lost during the third of these turns and the aircraft struck the ground in a steep nose-down attitude. Fire broke out on impact and engulfed the wreckage. The subsequent investigation did not reveal any evidence of a pre-impact defect or malfunction of the aircraft which might have contributed to the accident. Several of the pilots who observed the flight reported that the final manoeuvres performed were outside the normal operating parameters of the helicopter, and were conducted at an unsafe height above the ground. It was, however, not possible to establish which of the pilots was flying the aircraft at the time of the accident.

The helicopter was being flown along a watercourse at a height of about 10 ft and an airspeed of about 85 kt. As the pilot rotated the aircraft to commence a climb the rear of the landing skids struck the water. The helicopter pitched forward, overturned and sank. The water surface at the time of the accident was smooth and glassy. The judgement of height above such a surface is difficult. The inexperienced pilot was apparently aware of these difficulties, however, on this occasion misjudged the height of the helicopter above the water as he selected the climb attitude.

The pilot was to conduct seeding operations on a friend's property. On arrival at the strip, he removed the front right seat from the cabin, leaving only the pilot's seat in the aircraft (the rear passenger seats were not in the aircraft). The pilot then fitted shaped metal sheets to the top and bottom of the baggage door. The door was positioned at the rear of the cabin on the left side of the aircraft. The metal sheets enabled the door to be held open (at an angle of about 17`) during flight, to allow seed to be dispensed through the opening.

The seed mixture was contained in bags, each weighing about 45 kg. Four bags were loaded into the aircraft cabin. One bag was placed adjacent to the baggage door. The person dispensing the seed then sat on the cabin floor leaning against the cabin rear bulkhead. Two further bags were placed on the floor in the area normally occupied by the rear passenger seats and another bag on the floor in the position of the front right seat. About 10 min after the aircraft departed for the seeding area, the property owner became concerned that he had not seen or heard the aircraft and commenced a search. He located the wreckage some 25 min later.

From the evidence available at the site, the aircraft impacted the ground at low speed and with a high rate of descent. Some flap (probably one notch on the selection handle) was selected at impact but whether this was a normal configuration for seeding operations could not be determined. The impact was not survivable, the forces being sufficient to cause the pilot's inboard lap safety belt attachment bracket to fail in overload.

Examination of the seed bags indicated that one bag was probably empty of seed at impact. Nothing to indicate a pre-existing defect in the aircraft controls or engine was found. It appears that the pilot had conducted one seeding run and was conducting a right procedure turn to position for the next run when the accident occurred. It was established that the pilot had received no formal training in low flying or aerial agriculture techniques. The exact sequence of events leading to this accident could not be determined.