<sod >Police have now set up evidence tents at the site Police at the scene very close to the crash site in Buckinghamshire woodland today.< eod>< sod > Police have now set up evidence tents at the site A piece of fin, thought to be the tail-end of the small, Cessna plane involved, was visible A plume of smoke was seen over the woodland shortly after the two aircraft came down The local resident added: 'My mother said a man, who I think was someone who had been out walking nearby, went running up to the manor to say there had been a crash. Everyone is now 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>