Several feared dead after a plane and a helicopter have collided mid-air at Waddesdon on Friday. Emergency services were called to the site near Waddesdon Manor, near Aylesbury. The Air Accidents Investigation Branch (AAIB) said it was sending a team to investigate. Ambulance crews said there had been a number of casualties. A Wycombe Air Park spokesman said both aircraft involved in collision came from the airfield near High Wycombe Air Park shortly after midday. The police cordoned the area and took up investigation.