<sod > This helicopter disappeared off radar at 12pm today whilst flying over Waddesdon 15 minutes after it took off from Wycombe Air Park, which has confirmed its aircraft were involved  The aircraft came down on land near Waddesdon manor to the north west of London A spokesman for Thames Valley Police said: 'Officers are currently at the scene of an air accident near the village of Waddesdon near Aylesbury.< eod>< sod >  This helicopter disappeared off radar at 12pm today whilst flying over Waddesdon 15 minutes after it took off from Wycombe Air Park, which has confirmed its aircraft were involved This Cessna 152 took off from the same airfield around the same time as the helicopter This was the scene at the airfield where the planes took off this afternoon.< eod>