BE20, vicinity North Caicos British West Indies, 2007
BE20, vicinity North Caicos British West Indies, 2007
On 6 February 2007, a Beech King Air 200 on a scheduled passenger flight crashed into water soon after making a dark night VMC take off and initial climb from North Caicos. The Investigation noted that the regulatory requirement for a crew of two pilots had been ignored and that the pilot had probably consumed alcohol within the permitted limits prior to the take off. It was concluded that he had probably lost spatial awareness and been in the process of attempting recovery to the originally intended flight path when impact occurred.
On 6 February 2007, a Beech 200C Super King Air being operated by a small locally-based airline on a passenger flight from North Caicos to Grand Turk, Turks and Caicos Islands, British West Indies crashed into a shallow lagoon 1nm south east of the departure airport soon after a dark night take off in Visual Meteorological Conditions (VMC). The single pilot was fatally injured as a result of the accident whilst four out of the five passengers received serious injuries and the other, seated at the back of the aircraft, received only minor injuries.
An Investigation was carried out in accordance with Annex 13 principles by a local team appointed by the Turks and Caicos Civil Aviation Department which, under the terms of a pre-existing Memorandum of Understanding, included two UK AAIB Inspectors. No Flight Data Recorder (FDR) or Cockpit Voice Recorder (CVR) was required to be fitted to the accident aircraft and a CVR which had remained in the aircraft since acquisition from a previous owner and was recovered was found not to be in working order.
It was established that although the aircraft was principally used by the Operator to provide scheduled passenger services within the Islands, in the case of the accident flight, it was transporting a private party free of charge and so was considered by the Operator to be a private flight. A public transport flight at night would have required two pilots and upon examination of the locally applicable regulations, it was found that the flight had, in fact, been a public transport flight.
It was noted that soon after takeoff, the aircraft had been seen to start a turn to the right, which was consistent with its routing to Grand Turk but the aircraft reached an abnormally large angle of bank and began a descent which continued until it crashed.
It was noted that the aircraft fuselage had come to rest comparatively intact, although inverted and that site evidence indicated that the aircraft had struck the water in a nominally upright attitude at only a moderate rate of descent but with relatively high forward speed. Detailed examination of the wreckage and the circumstances of the accident led the Investigation to conclude that the aircraft had been structurally intact and probably under control when it struck the surface with both engines producing power throughout the short flight and at the time of impact. It transpired that most of the passengers had remained unaware of the impending crash.
The circumstances of the accident suggested to the Investigation that the pilot became spatially disorientated to the extent that the aircraft diverged from its intended flight path and reached an irrecoverable situation. It was considered that prevailing environmental conditions were conducive to a disorientation event and a postmortem toxicological examination also showed that the pilot had a level of blood alcohol which, although below the prescribed limit, was significant in terms of piloting an aircraft and would have made him more prone to disorientation.
The Investigation followed the following general reasoning in reaching its conclusion about the circumstances which led to the accident:
“The available evidence, which shows that a significant change in aircraft attitude occurred late in the accident sequence, strongly suggests that the pilot was in control of the aircraft when it struck the surface, and was taking appropriate recovery action. Some conclusions may be drawn from this: the aircraft was controllable; the pilot was physically able to control it and was so doing; and he probably had sufficient information from the flight instruments, alone, to make correct control inputs.
The event which caused the actual and intended flight paths to diverge was not catastrophic. There were no unusual engine or other noises in the cabin, no particularly unusual forces were experienced by the aircraft occupants and there were probably no warning lights or sounds in the cockpit. Together with the lack of obvious concern on the part of the pilot as the flight path diverged, this indicates a subtle event or situation which developed unchecked until recognised by the pilot at a late stage, and even then possibly not fully.
It was not possible to rule out a subtle technical malfunction as a contributory factor, but the weight of evidence indicated that the pilot retained sufficient reliable information from his flight instruments to prevent or correct the attitude deviation which ultimately led to the accident. Similarly, it was not possible to rule out a subtle but transient medical condition which may have interfered with the pilot’s normal functioning, although there was only circumstantial evidence to support the possibility.
The circumstances of the accident strongly suggest that the pilot became spatially disorientated. It was immediately after takeoff, it was dark with no reliable outside references and the pilot was operating as single crew. He had completed the after takeoff checks shortly before, which may have been an initiating distraction. It was probable that he had consumed alcohol at some time before the flight and his blood alcohol level, although not excessive, would have made him more prone to becoming disorientated. Although very experienced, the pilot had a potential weakness in his instrument scan technique. This and the turbulence the aircraft apparently encountered could also have contributed to any disorientation.
Spatial disorientation accidents are frequently fatal, as the pilot does not recognise the danger or is unable to effect a recovery. In this case the pilot did start a recovery and appears to have been taking appropriate recovery actions when the aircraft struck the surface. This had the effect of reducing the descent rate and placing the aircraft in an almost level attitude at impact. The pilot’s actions, although initiated too late to avoid the accident, lessened the impact damage and helped preserve the fuselage structure relatively intact, which probably prevented greater loss of life."
The following Causal Factors were identified:
- The aircraft adopted an excessive degree of right bank soon after takeoff. This led to a descending, turning flight path which persisted until the aircraft was too low to make a safe recovery.
- The pilot probably became spatially disorientated and was unable to recognise or correct the situation in time to prevent the accident.
Contributory Factors were also identified:
- The environmental conditions were conducive to a spatial disorientation event.
- The pilot had probably consumed alcohol prior to the flight, which made him more prone to becoming disorientated.
- The flight was operated single-pilot when two pilots were required under applicable regulations. The presence of a second pilot would have provided a significant measure of protection against the effects of the flying pilot becoming disorientated.
The Final Report of the Investigation was published on 19 May 2010 and may be seen in full at SKYbrary bookshelf: Aircraft Accident Report 2/2010
No Safety Recommendations were made.