Synopsis
A Robinson R44 Raven I, registration G-OUEL, departed from a private site near Hawick, Scotland, on a visual flight rules (VFR) flight to Barton Airfield in Manchester. The helicopter initially flew south at approximately 1,500 feet above mean sea level. As it approached hills where cloud tops were reported covered by low cloud, the pilot turned away from the planned route and likely entered cloud. The helicopter then accelerated, entered a rapid descent, and the main rotor blades struck the tailboom. The tailboom partially detached, the rotors nearly stopped, and the helicopter impacted the ground at the bottom of a valley, fatally injuring the pilot.
History of the Flight
The pilot had flown G-OUEL from Wycombe Air Park to the private site near Hawick on 28 July 2003. On 29 July, he made three local flights, including a sight-seeing trip. On the morning of 30 July, the weather was poor with low cloud and drizzle. The pilot delayed departure and eventually took off at 0956 UTC. The helicopter was equipped with a GPS navigation system that recorded time, position, groundspeed, track, and altitude every 30 seconds. Data showed the helicopter followed the A7 road south at groundspeeds of 107–116 knots until Teviothead. It then climbed from 1,500 to 2,400 feet in 30 seconds while turning right. The final recorded data point at 1004 UTC showed an altitude of about 2,450 feet, a groundspeed of 120 knots, and the helicopter still turning. Witnesses heard the engine stop suddenly with a bang resembling a rifle shot. The wreckage was discovered later by a farmer.
Other Air Traffic
Several military aircraft were operating in the area, including a Chinook helicopter and two fast-jets, but none influenced the flight. Radar data showed only one possible contact for G-OUEL at 1004 UTC. No eyewitnesses observed the final moments of the flight.
Weather
A meteorological aftercast indicated an area of low pressure with an occluded front over the English-Scottish borders, producing outbreaks of rain and drizzle with hill fog over high ground. Cloud was generally scattered or broken at bases between 1,200 and 2,500 feet. The wind was light from the northeast. A Chinook commander who transited the same route reported low cloud covering hill tops, requiring a descent in good visual conditions north of Hawick.
Investigation
No signs of pre-accident mechanical malfunction were found, but extensive post-crash fire damage limited a full assessment of serviceability. The available evidence indicated that the accident followed a main rotor blade strike on the tailboom, probably caused by excessively low rotor RPM. The loss of control and low rotor RPM may have resulted from spatial disorientation and mishandling of the controls, but the possibility that aircraft malfunction contributed could not be eliminated.