What happened
On the night of 3 March 2004, an Agusta A109E helicopter, registration G-PWER, was conducting a private flight from Battersea Heliport to Bournemouth Airport. The flight was being conducted under Special VFR (SVFR) conditions. As the aircraft approached Runway 26, the pilot was tracking the extended centerline of the runway at an altitude between 800 and 1,000 feet.
During the approach, the pilot reported becoming visual with the airfield, but radar data subsequently showed the aircraft entering a significant left-hand turn. During this maneuver, the aircraft's altitude dropped from approximately 1,000 feet to 400 feet before climbing slightly and then continuing a descending spiral. The pilot made several urgent radio transmissions, including a request for a climb, but the aircraft ultimately struck a grass field at high speed in a nose-down, banked attitude. The crash resulted in two fatalities, involving both the pilot and the passenger.
The investigation
The AAIB examined the wreckage and the aircraft's maintenance history. Investigators found no evidence of mechanical failure, engine malfunction, or unauthorized interference with the aircraft systems. Both engines were found to be operating normally at the time of impact. While the aircraft had experienced a loss of cockpit displays several weeks prior, testing confirmed that the electrical issue had been rectified and was not present during this flight.
Investigators also analyzed the meteorological conditions, noting that an occluded front had moved through the area, bringing light rain and reducing visibility. The investigation focused on the pilot's flight experience and the transition from visual to instrument-based flying in a degraded environment.
Findings
- The aircraft encountered a significant deterioration in weather conditions during the final stages of the approach.
- The pilot likely experienced spatial disorientation due to the loss of external visual references while attempting to navigate using limited ground lights or flight instruments.
- The pilot's limited experience in instrument flying was insufficient to manage the transition into a degraded visual environment.
- The operation of the LOW RPM warning horn was likely triggered by the specific power requirements of the aircraft's maneuvers, rather than an actual engine failure.
Safety action
- The Civil Aviation Authority (CAA) was advised to review the Rules of the Air regarding helicopters, specifically considering the implementation of minimum in-flight visibility requirements for both day and night operations to prevent inadvertent flight into instrument meteorological conditions (IMC).