The pilot was conducting a visual flight rules (VFR) flight from Walgett to an airstrip near Merriwa. The aircraft had departed from Walgett earlier in the day, but had returned a short time later when it was reported that the weather at the destination was not suitable for VFR flight. The pilot felt that he was under pressure to complete the flight that day. He continued to monitor the weather by telephoning for weather reports that were available from an automatic Bureau of Meteorology outlet, and by contacting a friend near the destination airfield. The aircraft later departed at about 1415. A search was subsequently initiated when the aircraft failed to arrive at its destination. The wreckage of the aircraft was located two days later on the top of a ridge, 3,880 ft above mean sea level (AMSL), slightly to the left of the direct track between Walgett and Merriwa.
The aircraft was found to have collided with trees during a right turn, at a rate of descent of about 2,500 ft/min. The impact severed the outboard section of the right wing. The aircraft had then collided with other trees before striking the ground. The right fuel tank had ruptured during descent through the trees and an intense post-impact fire had consumed the cabin area and the fuselage section immediately behind the cabin. Although the accident was survivable, both the pilot and passenger received extensive burns while escaping from the burning wreckage. The pilot died some time later from his injuries, before the aircraft was located by search-and-rescue services personnel during the morning of the second day of the search. A fixed emergency locator transmitter (ELT), mounted in the aft cabin area of the aircraft, was destroyed by the fire. While it was not possible to determine if the ELT had activated during the accident sequence, no signal from the ELT had been received by the satellite monitoring system. The pilot was known to possess a personal ELT; however, this was not located after the accident.
Examination of the wreckage did not reveal any deficiencies that were likely to have contributed to the accident. Data extracted from a portable global positioning system unit found at the accident site confirmed that the aircraft had been in a right turn when it collided with the trees. Shortly after the accident the pilot had written a brief message on the left tailplane of the aircraft. That message indicated the pilot's perception of the accident sequence, and was generally consistent with the analysis by the investigation team.
The pilot held a private pilot licence for aeroplanes, and a commercial helicopter licence, together with valid medical certificates; however, he did not hold a rating for flight in instrument meteorological conditions (IMC), nor was the aircraft approved for flight in IMC.
Reports from National Park rangers who were in the area at the time of the accident, and from the Bureau of Meteorology, indicated that the cloudbase was 3,600 ft AMSL, and that cloud was covering the ridge where the wreckage was found. The weather over lower terrain to the south-west of the accident site was reported to have been suitable for VFR flight.
The circumstances of this accident were consistent with uncontrolled collision with terrain following inadvertent flight into cloud. The pilot was primarily dependent on being able to see the ground or the horizon in order to maintain control of the aircraft. Once the aircraft entered cloud the pilot was no longer able to rely on external visual references and probably became spatially disoriented. The aircraft subsequently entered a right turn, descended rapidly and collided with trees.
The pressure that the pilot felt to complete the flight that day may have influenced him when choosing the shortest direct route over high terrain with associated poor visibility, rather than a longer route further to the south-west where clearer conditions prevailed.
- The pilot felt that he was under pressure to complete the flight that day.
- The pilot and the aircraft were only authorised for flight in visual meteorological conditions.
- Visual reference with the ground or the horizon was lost when the aircraft inadvertently entered cloud.
- The pilot probably became spatially disoriented and was unable to maintain adequate control of the aircraft when visual reference to the ground was lost.
As a result of this occurrence, the Bureau of Air Safety Investigation is currently investigating a perceived safety deficiency relating to operational issues associated with aircraft emergency locator transmitters.
Any safety output issued as a result of this analysis will be published in the Bureau's Quarterly Safety Deficiency Report.
|Date:||02 January 1999||Investigation status:||Completed|
|Time:||1610 hours ESuT|
|Location:||37 km E Coolah, Aero.|
|State:||New South Wales||Occurrence type:||Collision with terrain|
|Release date:||28 September 1999||Occurrence category:||Accident|
|Report status:||Final||Highest injury level:||Fatal|
|Aircraft manufacturer||Piper Aircraft Corp|
|Type of operation||Private|
|Damage to aircraft||Destroyed|
|Departure point||Walgett, NSW|
|Departure time||1415 hours ESuT|
|Role||Class of licence||Hours on type||Hours total|