What happened
On 29 April 2017, a Rotorsport UK MTOsport, registration G-RMTO, departed from Oxenhope Airfield in West Yorkshire for a private flight. The pilot and one passenger intended to fly north to observe fell running races. At the time of departure, weather conditions were reported as good, characterized by high-level overcast clouds and a light south-westerly breeze.
As the aircraft approached the vicinity of Great Knoutberry Hill, which has an elevation of 2,205 ft, the pilot was flying at 1,700 ft amsl over lower ground. During a course change toward the hill, the pilot noticed that the airspeed had dropped from 70 mph to between 55 and 60 mph. Realising the aircraft was below the summit height, the pilot applied full power in an attempt to climb. However, the aircraft struck a fence located on the summit before impacting the ground. Both the pilot and the passenger sustained minor injuries and were able to exit the wreckage unassisted.
The investigation
The AAIB investigation was based on the aircraft accident report submitted by the pilot and further enquiries. The investigation examined the flight path, the aircraft's performance during the climb, and the pilot's monitoring of flight parameters. The wreckage sustained damage to the rotors, upper assembly, propeller, nacelle, and the nosewheel, which had detached upon impact.
Findings
- The pilot was relatively inexperienced in hill flying, with only 79 total flying hours.
- The pilot failed to adequately monitor the aircraft's airspeed during the approach to the hill.
- The decay in airspeed prevented the aircraft from maintaining the necessary climb gradient to clear obstacles on the summit.