British European Airways Flight 706

British European Airways

Industry	Airline
Founded	1946
Headquarters	London , England, United Kingdom

Template:EngvarB Template:Infobox aircraft occurrence British European Airways Flight 706 (BE706/BEA706) was an international passenger service operating between London, England, and Salzburg, Austria. On 2 October 1971, while flying at approximately 19,000 feet (5,791 m), the rear pressure bulkhead of the Vickers Vanguard failed at the aft section of the cabin. This breach caused rapid decompression in the tail area, leading to the detachment of the tailplane surfaces. Consequently, the aircraft entered an uncontrollable dive and crashed near Aarsele, Belgium, resulting in the deaths of all 63 passengers and crew members on board. Debris from the aircraft struck a vehicle passing below, causing minor injuries to one occupant.

The British Air Accidents Investigation Branch (AAIB) determined that undetected corrosion located at the rear pressure bulkhead was responsible for its failure. The inspection methods employed by BEA failed to reveal this corrosion. Repeated pressurization cycles gradually expanded cracks in the bulkhead, weakening its structural integrity until it could no longer endure continued stress.

Aircraft

The aircraft involved was a Vickers Vanguard model 951, bearing the UK registration G-APEC. Constructed in 1959 with serial number 706, it was delivered to British European Airways in 1961.

Flight

Flight 706 departed from London Heathrow Airport's Runway 28L (currently 27L) at 09:34 local time, carrying 55 passengers alongside 8 crew members. Following takeoff, the aircraft was directed along the "Dover One" standard instrument departure route, passing Epsom, Biggin, and Detling. At 09:54 local time, the crew reported their position over the Dover VOR while climbing through an altitude of approximately 14,200 feet (4,328 m). Subsequently, at 10:01, control of communications was transferred to Brussels Air Traffic Control.

• 10:01 BEA706: "Good morning 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 next confirmed passing over the Wulpen VOR, maintaining a flight level of FL190 (approximately 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"

Around five minutes after this communication, Flight 706’s crew transmitted urgent distress messages to Brussels Tower stating "we're going down, seven oh six, we are going down." They issued multiple "mayday" calls and repeatedly indicated loss of control. At one moment, they reported having no rudder control. Several background voices could be heard during these transmissions.

• 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 final transmission from Flight 706 was received at 10:10:30. Following this, Brussels Tower made several attempts to reestablish contact but received no response. Ground witnesses observed that the aircraft’s tailplane had separated before it entered a steep nose-dive. The plane continued descending rapidly until it crashed into farmland near Aarsele, Belgium, resulting in an explosion upon impact. All 63 individuals on board—55 passengers and 8 crew—perished. Additionally, debris struck a vehicle on the ground causing injury to at least one person.

Emergency responders were promptly dispatched to the scene. Investigators arrived to recover the aircraft’s flight data recorder. A crisis center was established in Salzburg to assist relatives of those aboard Flight 706. Search teams reported that most bodies recovered were severely fragmented; one rescuer commented that the remains found so far were insufficient to reconstruct even a single complete body.

Passengers and crews

Onboard the aircraft were 55 passengers accompanied by 8 crew members. Initial reports indicated that 37 of the passengers were British nationals. Additionally, there were at least 4 Japanese and 11 American travelers. Further information confirmed that 8 Austrian citizens were also among those on board. Among the deceased were several prominent individuals, including the British milliner Otto Lucas, the chemist Albert Wassermann who was born in Austria, and the Austrian scholar Template:Interlanguage link multi.

The flight crew consisted of Captain E.T. Probert, aged 40, who had logged a total of 9,260 flying hours, with 1,927 hours specifically on this aircraft model. The first officer was J.M. Davies, 38 years old, certified on the Vickers Vanguard, with an overall flying experience of 3,386 hours, including 764 on the Vanguard. Also on board was a third pilot, B.J.S. Barnes, aged 27, who had accumulated 2,237 total flight hours and 1,903 hours on this type of aircraft. Additionally, a supernumerary crew member named Captain G. Partridge was present during the flight.

Investigation

Eyewitnesses observed that the Vanguard abruptly disintegrated in mid-flight, losing one wing before crashing to the ground while emitting smoke from one wing. They reported hearing unusual sounds during the incident. According to these witnesses, the plane initially touched down in a field before crossing a road and continuing across approximately 500 yards (1,500 ft; 460 m) of grassland. The aircraft left deep gouges in the terrain and ultimately ignited in a pit about 15 feet (4.6 m) deep. One observer described the fire spreading "like waves" from the wreckage. Authorities noted that eyewitness accounts suggested Captain Probert attempted an emergency landing prior to the crash.

There was significant speculation about possible sabotage by extremist groups. A representative from BEA suggested that Northern Ireland extremists linked to the Provisional Irish Republican Army might have targeted the aircraft. Although this Vanguard had previously served on the London-Belfast route, it had not operated on that route for at least two days and had been stored in Edinburgh as of Friday. Nonetheless, after an initial inquiry led by William Trench of the Air Accidents Investigation Branch (AIB), no evidence emerged to support claims that sabotage contributed to the accident.

Structural failure

Analysis of the debris from the aircraft revealed that roughly two-thirds of the tail section, including the left elevator, had detached before the plane impacted the ground, indicating an in-flight structural disintegration. These components were discovered trailing ahead of the main crash site, with significant fragments located several kilometres away from the primary wreckage. When factoring in the prevailing wind drift, the drift plot analysis suggested that these parts separated at an altitude near 18,000 feet (5,500 m). This conclusion was further corroborated by data from the flight recorder and transcripts of communication between the flight crew and Brussels air traffic control. Notably, the flight data recorder ceased abruptly while cruising, and in the ATC recordings, the crew reported descending vertically without rudder control.

Inspection of the recovered components showed that both left and right horizontal stabilizers along with their elevators had detached in a comparable manner. The characteristics of these separations strongly implied that the failure originated internally rather than from external forces. Specifically, the upper skin of the tail was blown outward, indicating a pressure differential inside the aircraft as a likely cause for the detachment.

Reconstruction efforts focused on the wreckage revealed corrosion damage on the lower section of the rear pressure bulkhead. The area beneath the double curvature peripheral doubler plate exhibited material degradation and weakened bonding between layers. At each corroded segment’s end, tears extended upward and outward toward a rivet line positioned at the bulkhead’s lower edge. The tear on the left side displayed distinctive "step" marks extending for at least 60 centimetres (24 in), with each step’s spacing progressively increasing.

The AAIB conducted a simulation replicating similar conditions using an ultraviolet tracer to visualize tear propagation. A right horizontal stabilizer from another aircraft of comparable age and flight hours was utilized. During this test, differential pressure was applied until failure occurred: the bulkhead ruptured violently, causing an outward burst that blew out the tail skin. The force was strong enough to cause a rivet line to puncture through the elevator hinge skin. This explosion severely damaged both the right horizontal stabilizer and elevator. Patterns produced during this simulation closely matched those observed in the actual wreckage.

These findings conclusively demonstrated that corrosion within the rear pressure bulkhead triggered an in-flight structural failure, resulting in an explosive event that rapidly separated both horizontal stabilizers and the vertical stabilizer. The subsequent loss of critical aerodynamic surfaces led to destabilization and loss of control by the flight crew.

Cause of failure

The severity and extent of the corrosion suggested that it had developed over an extended duration, although investigators were unable to specify the exact timeframe required for such deterioration to occur. The radiographic inspection method utilized by BEA failed to identify the crack promptly, as the radiographic images were not correctly interpreted. Consequently, the crack progressively expanded due to repeated pressurization cycles until it became externally visible. This conclusion was supported by the presence of nicotine stains and evidence of spilled sewage near the corroded section.

Despite the external visibility of the cracks, routine visual inspections by personnel were infrequent. Instead, inspections were spaced over long intervals, allowing corrosion damage to worsen. Over multiple flights, a significant accumulation of sewage fluid remained on the corroded surface, producing noticeable staining. However, this stained area was consistently cleaned prior to inspections, preventing aircraft inspectors from detecting any corrosion or potential fluid leaks in that region.

Conclusion

The investigation ultimately determined the cause of the accident and stated,

"The accident resulted from the failure of the rear pressure bulkhead, which caused both tailplanes to detach during flight and led to the aircraft's subsequent crash,"

Aftermath

British European Airways promptly adopted an enhanced corrosion detection procedure. It was subsequently disclosed that eight other Vanguards in their fleet exhibited similar cracking issues as observed on G-APEC.

Following publication of the final report, AAIB introduced a new method for identifying corrosion and cracks. They also mandated modifications to improve ground engineers' access to hard-to-reach areas within the aircraft structure.

See also

• China Airlines Flight 611
• Japan Airlines Flight 123

External links

• British European Airways Vanguard G—APEC. Report on the accident which occurred at Aarsele, Belgium on 2 October 1971" (Archive). The Kingdom of Belgium Ministry of Communications, Civil Aeronautics Administration. Re-published by the Accidents Investigation Branch, Department of Trade and Industry as Civil Accident Report No EW/A224, Report 15/72. – Official accident report.
  • Appendices (Archive)
• Video of the crash site, Associated Press