[6] The Pawnee had departed earlier on 9 August 1974 from Southend Airport to a disused airfield, formerly RAF Downham Market, situated near Broomhill and Bexwell, in Norfolk.

At about 14:04 the aircraft had finished spraying a field 6.5 miles (10.5 km) south of Downham Market and was returning to replenish the pesticide hopper.

[7] The Phantom departed RAF Coningsby at 13:51 to fly a low-level navigation and reconnaissance flight at no lower than 250 feet (76 m) above ground level.

About 14:08 about 1 km (1,100 yd) west of the village of Hilgay, and at an estimated height of around 300 ft (91 m) the Phantom, flying at a speed of about 420 kn (780 km/h), struck the Pawnee on its right side.

The Pawnee disintegrated, while the Phantom, on fire and shedding parts of its structure, continued on its heading for a further 1 kilometre (1,100 yd) before it hit the ground inverted.

But it was accepted that at a closing speed of about 400 kn (740 km/h) the time needed by the Pawnee pilot to assess the situation and execute a manoeuvre was minimal.

[2] While it accepted the need for the Royal Air Force to practise low level high-speed flying, the investigation report was concerned about the lack of information on the military low-flying route available to civil pilots, particularly those involved with crop spraying, pipeline, and powerline inspection.