On 2 October 1971, whilst en route at 19,000 feet (5,791 m),[1] the Vickers Vanguard the pressure bulkhead at the rear of the cabin failed.

The aircraft entered an uncontrollable dive and crashed near Aarsele, Belgium, killing all 63 passengers and crew on impact.

[2] A piece of debris from the aircraft struck a passing car, causing minor injuries to one of its occupants.

[4] The aircraft involved in the crash was a Vickers Vanguard type 951, registered in United Kingdom as G-APEC.

[5] Flight 706 took off from Runway 28L (now 27L) of London Heathrow Airport at 09:34 local time with 55 passengers and 8 crew members.

[5] After take off, Flight 706 was routed via Epsom, Biggin and Detling in accordance to the "Dover One" standard instrument departure clearance.

[8][9] Two notable fatalities among the passengers were the British hat designer Otto Lucas and an Austrian academic, René Marcic [de].

According to them, the aircraft touched down in one field, jumped a road, and plowed through grassland for 500 yards (1,500 ft; 460 m).

Police said eyewitness reports indicated that Captain Probert had tried to execute an emergency landing.

The Vanguard had been used on the London-Belfast route, though he said the aircraft had not been on Belfast service for at least 48 hours and was stored in Edinburgh on Friday.

[5][6] The examination on the recovered parts revealed that both the left and right horizontal stabilizer and the elevator had detached in a near similar manner.

The upper skin of the tail had been blown outwards, strongly suggesting that difference in internal pressure from the aircraft had caused the separation of the components.

At the end of each corroded area, a tear could be seen spreading upwards and outwards to a rivet line which was located at the lower edge of the bulkhead.

During the test, the bulkhead failed, creating a burst of force that blew the skin of the tail outwards.

This was corroborated by evidence of nicotine stain and signs of spilt sewage around the corroded area.

After numerous times of flying, a considerable amount of sewage fluid had been retained on the corroded area, creating visible stain.

[5] After the release of the final report, a new technique to detect corrosion and crack was introduced by AAIB.

They also ordered a modification to provide better access for ground engineers into difficult to reach areas within the aircraft.