What happened
On 23 December 2000, a Beech 200 King Air, registration VP-BBK, departed Blackbushe Airport for a private flight to Spain. The departure took place in heavy fog, with visibility reported at approximately 500 metres. As the aircraft accelerated down Runway 08 and reached the point of rotation, it began to bank sharply to the left. Shortly after lifting off, the aircraft disappeared into the fog and crashed into a factory complex roughly one nautical mile north-east of the airfield. The impact triggered a major fire that destroyed much of the aircraft. All 5 fatalities (the pilot and four passengers) occurred during the accident.
The investigation
Investigators examined the wreckage, the engines, and the cockpit voice recorder (CVR). While the aircraft was estimated to be approximately 632 lb over its maximum certificated takeoff weight, engineering analysis of the Pratt & Whitney PT6A-24 engines and the propellers revealed no mechanical failures or malfunctions. The engines and propellers were found to be functioning correctly at the time of impact.
Analysis of the CVR and spectral analysis of the propeller sounds provided critical evidence. The investigation established that at the moment of rotation, the rotational speed of one propeller decreased significantly. This created a thrust asymmetry. Furthermore, the investigation looked into the pilot's transition from visual to instrument flight and the potential for spatial disorientation due to the lack of external visual references in the fog.
Findings
- The primary cause of the asymmetric thrust was likely power lever migration, where the engine control levers moved aft due to insufficient friction being set on the control quadrant following recent maintenance.
- The pilot was attempting to transition from visual references to instrument flight in extremely low visibility conditions.
- The loss of control was exacerbated by potential spatial disorientation, possibly triggered by the pilot looking at engine instruments, which can create a false sensation of banking.
- Confusion may have been caused by the pilot's familiarity with different aircraft, specifically a different bank angle indicator orientation in a Piper PA-46.
- The pilot's workload increased significantly due to the unidentified technical event and the lack of visual ground references.