British European Airways Flight 706 (BE706/BEA706) was a scheduled international passenger flight from London, England to Salzburg, Austria. On 2 October 1971, whilst en route at 19,000 feet (5,791 m), the pressure bulkhead of the Vickers Vanguard at the rear of the cabin failed. The resulting depressurisation of the tail section caused the surfaces of the tailplanes to separate. The aircraft entered an uncontrollable dive and crashed near Aarsele, Belgium, killing all 63 passengers and crew on impact. A piece of debris from the aircraft struck a passing car, causing minor injuries to one of its occupants.
The British AAIB concluded that the failure of the rear pressure bulkhead had been caused by undetected corrosion located at the rear of the aircraft. The corrosion could not be noticed by crew due to the inspection technique that had been applied by BEA. Numerous pressurization cycles caused the crack to grow, weakening the rear pressure bulkhead until the structure was unable to withstand further repeated stress.
The aircraft involved in the crash was a Vickers Vanguard type 951, registered in United Kingdom as G-APEC. The aircraft was built in 1959 with a serial number of 706, and was delivered to BEA in 1961.
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. After take off, Flight 706 was routed via Epsom, Biggin and Detling in accordance to the "Dover One" standard instrument departure clearance. The crew of Flight 706 later reported over the Dover VOR at 09:54 local time. At the time, Flight 706 was climbing through 14,200 feet (4,328 m). At 10:01, the communication was handed over to Brussels Air Traffic Control.
10:01 BEA706: "Goodmorning Brussels Bealine seven oh six is passing one eight for one nine zero and estimating Wulpen at zero hour"
10:01 ATC: "Seven oh six cleared er Salzburg green one to maintain flight level one nine zero on reaching "
10:01 BEA706: "Bealine seven oh six"
The crew then reported passing over the Wulpen VOR with the aircraft level at FL190 (about 19,000 feet (5,791 m).
10:05 BEA706: "Brussels Bealine seven oh six checked Wulpen zero four we're now level one nine zero estimating Mackel one zero"
10:05 ATC: "Seven oh six roger"
Five minutes after this transmission, the crew of Flight 706 transmitted "we're going down, seven oh six, we are going down" to Brussels Tower. The crew later declared emergency and called "mayday, mayday" several times. The crew also stated the phrase "out of control" several times. At one point, they stated that there was no rudder control. Their calls were accompanied by several background voices.
10:09:46 BEA706: "We're going down, seven oh six, we're going down Mayday Mayday Mayday"
10:09 BEA706: "Mayday Mayday Mayday we're going down vertically"
10:09:55 BEA706: "Bealine seven zero six (inaudible) out of control"
10:09:58 BEA706: "No rudder-- (inaudible)"
10:10:11 BEA706: "AAH! This is it--"
The last transmission from Flight 706 was recorded at 10:10:30. Brussels Tower immediately attempted contacting Flight 706 several times. However, there were no answers from Flight 706. Witnesses on the ground saw the tailplane of Flight 706 detached and subsequently it entered a nose-dive. The flight kept diving and crashed into farmland near Aarsele, Belgium and exploded on impact. All 55 passengers and 8 crew members were killed. At least one person on the ground was injured after pieces of debris struck a passing car.
Rescue services were immediately dispatched. Investigators were deployed and searched for the aircraft's black box. A crisis center was set up in Salzburg for the relatives of the victims of Flight 706. Searchers stated that most of the bodies were not intact. One searcher said "as for the bodies, what we have found so far is barely enough to reconstitute one body."