<sod >A local resident told MailOnline: 'My father heard a loud bang. My mother said a man, who I think was someone who had been out walking nearby, then went running up to the manor to say there had been a crash. 'It didn't happen directly over the grounds, but in woodland nearby. My father ran up to the scene. Everyone is helping the emergency services.' Both aircraft involved had taken off from Wycombe Air Park, which is 16 miles to the south east of the estate, and were flying at low altitude.< eod>< sod > A local resident told MailOnline: 'My father heard a loud bang. My mother said a man, who I think was someone who had been out walking nearby, then went running up to the manor to say there had been a crash. 'My father ran up to the scene. It was clear pretty quickly that no one has survived. Everyone is now helping the emergency services.' Aerial footage from above the site where a helicopter and plane collided in mid-air this afternoon.< eod>