What happened
On 16 June 2006, a Robinson R44 Astro, registration G-ROZI, was conducting a private flight to York Racecourse to collect passengers. The flight began at Sandtoft Aerodrome, where the pilot had refuelled after calculating that the aircraft could operate safely despite high ambient temperatures and light winds.
During the final approach to the landing site at the racecourse, the pilot performed a northerly approach with a final turn to an easterly heading. As the aircraft levelled for the final hover before touchdown, a 'low rpm' warning activated, and the helicopter began to sink. Despite an attempt to increase power, the aircraft struck the ground with significant force. Following the impact, the engine RPM recovered, causing the helicopter to lift off again and turn approximately 9 and 0 degrees before the pilot regained control and completed a subsequent landing. There were no injuries to the pilot or the three passengers, but the airframe sustained extensive distortion damage.
The investigation
The investigation established that the pilot had planned the flight with the aircraft weight at 1,065 kg, which was near the maximum permitted gross weight of 1,089 kg. The pilot had also selected full carburettor heat prior to the descent. The investigation considered the environmental conditions, noting a temperature of approximately 20°C and light surface winds. The pilot later reflected that the heavy landing was caused by the combination of high ambient temperature, light wind, and the aircraft operating near its maximum weight limit.