The pilot with two passengers was conducting a private flight in a Piper Archer from Merimbula to Bathurst, to be carried out in accordance with the visual flight rules (VFR). The intended route was coastal to Wollongong and then direct to Bathurst. The latter part of the route passed over the Oberon area where the elevation of terrain was between 3,300 and 5,000 ft.
At about 0900 EST the pilot telephoned a relative near Katoomba to obtain an appreciation of the weather in the area. He was told the conditions were overcast but clear. About 20 minutes later the relative tried unsuccessfully to contact him to advise that light rain had begun falling.
The pilot and his passengers arrived at Merimbula airport at approximately 0930. He asked the locally based flying instructor for weather details and was shown a facsimile copy of the current Area 21 forecast, obtained at 0911 from the AVFAX briefing facility. At the pilot's request the instructor obtained terminal area forecasts (TAFs) for Wollongong, Bankstown and Bathurst from the AVFAX briefing facility at 0957. The Area 21 forecast, which was valid for the period 0900 to 2100, indicated that visual meteorological conditions could be expected along the planned route, with areas of rain and showers extending east across the forecast area. Isolated thunderstorms were also expected to develop over the ranges along the planned track, and to slowly extend east after 1300. Conditions at Mt Victoria, south-east of Bathurst, would be suitable for visual flight until 1400. The Bathurst TAF, issued at 0410 and valid from 0600 to 1800, forecast visual meteorological conditions to exist throughout that period.
The pilot did not seek any further weather information from the instructor and did not submit flight details. He was later seen refuelling and preparing the aircraft for flight. At 1028 the pilot advised flight service of his departure from Merimbula. That was the only recorded communication between the pilot and flight service.
At approximately 1230 witnesses south of Oberon reported seeing an aircraft flying very low and at times circling. They reported that it occasionally entered patches of low cloud and disappeared from view behind higher terrain. Some of the witnesses reported the engine sounded as if it was revving and cutting. Witnesses in the area to the south and west of Oberon subsequently reported several similar sightings of the aircraft at about that time. At 1256 witnesses on a property 9 Km west-north-west of Oberon reported hearing an aircraft overhead. They could not see the aircraft because of fog and mist but heard it circle their house twice. The engine noise increased followed by the distinct sound of an impact. They subsequently found the wreckage of an aircraft approximately 250 metres west of the house. The occupants of the aircraft were fatally injured.
The aircraft had collided with grass-covered sloping terrain at an elevation of 3,300 ft. Examination of the accident site and wreckage determined the aircraft had been descending in a left wing low attitude under high power and at high speed. No defect that may have contributed to the accident was found in either the aircraft or its systems.
An amended Bathurst TAF issued at 1018 forecast significantly deteriorating conditions after 1100. Unlike the earlier forecast, it indicated that from 1100 visual meteorological conditions in the Bathurst area would have been marginal and at times non-existent. Similar conditions were confirmed by witness accounts of weather in the Oberon area at the time of the accident, and by a later analysis of data by the Bureau of Meteorology. Conditions depicted by the Sydney weather radar at 1300 included an area of high intensity rainfall south of Oberon.
The pilot held a Private Pilot Licence and a valid Class 2 medical certificate. He had undertaken navigation training between February and June 1998. His instructor reported that the navigation training had been undertaken in mostly ideal weather and he had not been able to demonstrate flight in marginal weather. The pilot had, as part of his training, received 3.3 hours instrument flight instruction but was not qualified to fly in instrument meteorological conditions. He had not recorded any further instrument flight training since his licence test in June 1998.
Subsequently, the pilot undertook training in the Piper Archer. He had been shown the operation of the aircraft equipment including the use of the global positioning system (GPS) to assist navigation. Since gaining his private licence qualification the pilot had made three extensive interstate flights. The instructor reported the pilot was cautious about the weather and if the forecast was doubtful he would contact an instructor for advice. Apparently, on at least one occasion, when the weather was unfavourable, he had terminated the flight short of his destination. The pilot hired the aircraft for three days and was not expected to return from Merimbula until the day after the accident.
The pilot obtained the correct weather forecasts for the flight. The investigation found no record of the pilot having updated his weather information during the flight. Consequently, although he expected a gradual deterioration of the weather he would not have had any warning of the more rapid deterioration, and greater severity of conditions.
It is likely the pilot only realised that the weather was significantly different from the forecast when he was tracking across the higher terrain south-east of Oberon. Due to his lack of exposure to similar weather, it is possible he delayed making a decision to divert until too late. Having flown into those conditions the pilot then found himself trapped between the ridges and the cloud base, unable to continue or turn back. His instrument flight skills would have been inadequate to attempt flight in cloud under those conditions. When the aircraft entered cloud the pilot was no longer able to rely on external visual references and probably became spatially disorientated. The aircraft subsequently entered a left turn, descended rapidly and collided with the ground. The accident was consistent with loss of control following flight in instrument meteorological conditions by a non-instrument rated pilot.
- Weather conditions deteriorated more rapidly and more severely than was initially forecast in the weather reports obtained by the pilot.
- The pilot was unaware of amended weather information that accurately forecast the deterioration in weather conditions.
- The pilot continued flight into non-visual meteorological conditions
Local safety action
The danger to VFR pilots entering non-VMC under similar circumstances has been well documented as a result of many previous accident investigations. Inadequate preflight planning, poor in flight decision-making skills and poor judgement have all been identified as factors common to these types of accidents. As part of its safety promotion activity the Civil Aviation Safety Authority (CASA) is adapting to Australian conditions, an interactive computer based training program called "Weather Wise". This program was developed by the US Federal Aviation Administration from research into the nature of weather-related decision-making. It was specifically designed to assist visually rated pilots to recognise deteriorating weather conditions during flight and decide on a safe course of action. CASA intends to make the program available to pilots and flying schools for use as part of initial and recurrent training sequences.
|Date:||30 October 1999||Investigation status:||Completed|
|Time:||1256 hours EST|
|Location:||9 km WNW Oberon|
|State:||New South Wales||Occurrence type:||VFR into IMC|
|Release date:||31 October 2000||Occurrence class:||Operational|
|Report status:||Final||Occurrence category:||Accident|
|Highest injury level:||Fatal|
|Aircraft manufacturer||Piper Aircraft Corp|
|Type of operation||Private|
|Damage to aircraft||Destroyed|
|Departure point||Merimbula, NSW|
|Departure time||1025 hours EST|
|Role||Class of licence||Hours on type||Hours total|