Leonardo AW109SP Grand New crash near Sywell Aerodrome, Northamptonshire, United Kingdom

The pilot and an engineer had been performing flight maintenance checks that had been intermittently interrupted by heavy rain showers. Whilst performing a rotor blade check in the hover during a period of clear weather, the No 1 engine OIL HOT caption illuminated. After landing, a second engineer opened the engine cowl to conduct an inspection of the engine. Following this inspection, the helicopter took off again for a further maintenance check flight. During the flight, a small but unusual vibration was felt by the occupants. The pilot elected to return to land at the airfield, but during his approach a sudden very heavy vibration started. The pilot performed a run-on landing, with no further issues. Subsequently, the engine cowl was found to have contacted the main rotor blades due to it not having been correctly latched shut during the earlier inspection. AW109SP Grand New, G-IWFC 06-18