News that is currently developing:
A light aircraft and a helicopter were involved in a mid air collision over Waddeston Manor, Nr Aylesbury, today just after midday. ‘Multiple casualties’, with multiple ambulance and fire crews, including the Thames Valley Air Ambulance.
Police have a large cordon around the area however imagery shows several parts of the light aircraft scattered around the area:
The image shows presumable registration G-WACG, a Cessna 152 built in 1982, which is currently based at the airfield, under Airways Aero Associations, the company who runs Wycombe Air Park, the base airfield for this aircraft.
The AAIB has one report on file for this aircraft, A 1993 Accident report form sent in by the pilot. It details a front landing gear collapse failure caused via a rejected takeoff by the pilot, at Bodmin Airfield, Cornwall. He escaped with no injuries and the aircraft with damage to the front landing gear, propeller and engine cowling.
FlightRadar24 has tracking info for the aircraft; it appears it made 2 flights today around the local area, no destination was reported. It has 2 minutes of tracking data for what appears to be the fatal flight, showing the aircraft at 11:57UTC climbing normally through 3000ft, however at 11:59Z making a small turn left and rapidly losing altitude.
It is reported the other aircraft is G-JAMM, a Guimbal G-2 Cabri under Helicoper Services Ltd, a Helicopter leasing and training company. The aircraft is based at Wycombe also. (thanks @Balloonchaser)
FlightRadar24 data shows the aircraft travelling roughly the same direction as the other aircraft, at a constant 1000ft. Last contact was made at 12:00:46Z, almost exactly over the crash site.
This data together appears to show the C152 descending into the helicopter from above, when taking into account descent rates, altitudes and the higher speed of the C152. The descent from the C152 appears to be at a fairly steep rate. It is not known why this descent took place. This is my personal deduction, and should not be considered as reliable
Both aircraft reportedly departed from Wycombe Air Park (EGTB). It has one asphalt runway, and 2 other grass runways, with ATC service. It’s proximity to many VORs and NDBs, whilst situated around class G airspace and being below the London TMA makes it a popular and busy training location.
Images and info: http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-42024712, Google Earth