A helicopter which crashed killing the pilot and leaving four passengers seriously injured was over its weight limit, an investigation has found.

The former military Alouette aircraft crashed at Breighton airfield in East Yorkshire in July last year.

Witnesses said they heard a "crack" and a "very loud bang" after the aircraft performed several steep manoeuvres.

The main rotor blades hit the tail boom before the helicopter crash landed, the Air Accident Investigations Branch found.