What happened
On the evening of 19 April 1998, a Robinson R44, registration G-POWE, was involved in a fatal accident near Gumley, Leicestershire. The pilot, who had been using the aircraft for several flights throughout the day, had picked up three passengers from a hotel located between Leicester and Market Harborough. After a meal, the group returned to the helicopter at approximately 20:30 hrs. At the time of their return, it was raining.
Shortly after takeoff, a witness observed the helicopter flying through overcast and drizzly conditions. The aircraft was seen passing behind a line of trees, followed by the sound of engine stalling or spluttering, and then a loud crash. The helicopter struck a steep, grassy slope in a nose-down and left-bank attitude, descending at a high rate of speed. The impact was followed by a severe post-impact fire that destroyed much of the wreckage.
The investigation
Investigators examined the wreckage and the engine, finding that the Lycoming engine was still running at idle power at the moment of impact. The electrical system was functional, and the low rotor speed warning light was illuminated, indicating the rotor RPM had dropped below normal operating levels. There was no evidence of any mechanical failure or pre-impact disconnection of the flight controls or power transmission systems.
The investigation also looked into the weather conditions. While the weather had been suitable for flight earlier in the day, a frontal system had moved into the area, bringing rain and lowering the cloud base significantly. By the time of the accident, the cloud base was estimated to be between 300 and 600 feet, and visibility was reduced by rain.
Findings
- The pilot was flying at night in weather conditions that were unsuitable for the planned flight.
- The aircraft was flying in an area with very limited ground lighting and significant terrain obstacles.
- The pilot likely experienced spatial disorientation due to the lack of external visual references caused by the low cloud and darkness.
- The possibility of carburettor icing cannot be ruled out, as the weather was conducive to ice build-up and the carburettor heat was in the 'hot' position at impact.
- Misting of the helicopter canopy due to high humidity and wet clothing may have further distracted the pilot or obscured vision.