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Analysis

Summary

Entries in the pilot's logbook indicated that in the past, the pilot had been prepared to abandon flights due to poor weather. This provided some support for the contention by those who knew the pilot that he was cautious with respect to weather. The weather forecasts obtained by the pilot did not indicate that conditions were unsuitable for the flight, and the decision to proceed at that stage was probably appropriate. However, the pilot had reported that the weather conditions while overhead Goondiwindi, approximately one hour before the accident, were not good. It should have become apparent to him as he continued towards the coast that the weather conditions were deteriorating to the point where they were unsuitable to continue the flight.

The investigation was not able to determine why the pilot made a decision to continue with the flight when confronted with weather conditions that were obviously worse than those forecast, and that appeared to be unsuitable for VFR flight.

The pilot's initial handling of the aircraft when in IMC appeared reasonable under the circumstances. The left turn to intercept the track from Toowoomba to Caloundra was performed with a degree of accuracy and was indicative that the pilot was probably using the GPS for navigation. The steady heading and slow but constant rate of descent which were evident after the aircraft was established on track to Caloundra suggested that the aircraft was probably being flown on autopilot.

The subsequent failure of the pilot to fly the assigned heading, the increased ground speed and rate of descent, and the consequent loss of control are consistent with the pilot becoming spatially disoriented during the right turn onto 130 degrees and having disconnected the autopilot. The aircraft impacted the ground in close proximity to the last radar-observed position, less than 90 seconds after the pilot's last radio transmission was received by ATS. Based on witness reports and evidence at the accident site, the aircraft was in a left spiral dive before impacting the ground.

The pilot of a VFR aircraft is solely responsible for ensuring that the flight is operated with due regard for changing weather conditions. In this particular instance, for reasons that were not established, the pilot placed himself in a situation where weather conditions were unsuitable for VFR flight; a situation for which he was not trained or qualified. Having placed himself in that situation, the ATS response became a matter of primary importance. ATS staff play a vital role in assisting pilots in an in-flight emergency situation. The timeliness and effectiveness of that assistance is particularly important when dealing with VFR pilots as they are subject to unique emergency situations and often have limited skills and experience. In addition, as VFR pilots generally operate as a single crew, they rely heavily on external assistance when faced with emergency situations such as inadvertent flight into IMC.

The ATS response to this in-flight emergency would have been enhanced through a greater understanding and application of the strategies and techniques suggested in the Manual of Air Traffic Services, the IFER training manual and the IFER checklist. Controller actions suggested that they did not have the background knowledge to effectively manage the in-flight emergency situation. In particular, the controllers did not appear to be aware of the potential consequences and therefore the priority that needed to be afforded to the pilot.

The strategy adopted by the controller in responding to the in-flight emergency situation was not consistent with the guidance provided in chapter 17 of the Manual of Air Traffic Services, the IFER training manual or the IFER checklist in use. In particular, the pilot was placed in a situation where he was turning and descending the aircraft at the same time. In addition, the pilot was also required to respond to questions from ATS while performing these manoeuvres. It was unlikely that the pilot had the skills or experience that were required to enable him to cope with these demands. Although the controller's communication style was in accordance with standard phraseology, the authoritative and interrogative style was inappropriate in the circumstances and was unlikely to have instilled confidence in or reassured the pilot.

Although the Manual of Air Traffic Services provided basic guidance on the strategy needed to deal with a VFR pilot operating in IMC and although the IFER checklist served as an aide-memoire, neither provided the level of detail contained in the IFER training manual. It is significant that this, or an ADF equivalent, manual was not available to ADF ATS units.

The circumstances of this accident are consistent with an uncontrolled collision with terrain following the pilot's loss of adequate external visual reference. It is likely that he became spatially disoriented and lost control of the aircraft soon after descending through 3,200 ft. The aircraft subsequently entered a left spiral dive before impacting the ground. As a result of concerns regarding military air traffic control officers' awareness of in-flight emergency response practices and procedures for civil aircraft, the Australian Transport Safety Bureau issued interim recommendation IR19990190 to the ADF on 16 December 1999.

 
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