On 3 July 1968, BKS Air Transport Flight C.6845, an
Airspeed Ambassador
The Airspeed AS.57 Ambassador is a British twin piston-engined airliner that was designed and produced by the British aircraft manufacturer Airspeed Ltd. It was one of the first postwar airliners to be produced.
The Ambassador was developed i ...
registration ''G-AMAD'' of
BKS Air Transport BKS may refer to:
* BKS theory, on interaction of matter and electromagnetic radiation
* BKS Air Transport, UK airline 1951-1970
*BKS (band), a Canadian techno group created by radio DJ Chris Sheppard, with Hennie Bekker and Greg Kavanagh
*BKS, Fa ...
crashed at
Heathrow Airport
Heathrow Airport (), called ''London Airport'' until 1966 and now known as London Heathrow , is a major international airport in London, England. It is the largest of the six international airports in the London airport system (the others be ...
, damaging two parked
Trident
A trident is a three- pronged spear. It is used for spear fishing and historically as a polearm.
The trident is the weapon of Poseidon, or Neptune, the God of the Sea in classical mythology. The trident may occasionally be held by other marine ...
airliners as it cartwheeled into the incomplete
Heathrow Terminal 1
Heathrow Terminal 1 is a disused airport terminal at London Heathrow Airport that was in operation between 1968 and 2015. When it was officially opened by Queen Elizabeth II in April 1969 it was the largest new airport terminal in western Euro ...
, then under construction. Six of the eight people on board the Ambassador were killed, along with the eight racehorses being transported on it.
[ citing ''Aircraft Illustrated'' Vol.1, nr. 4 (Oct. 1968), p.127] The crash was blamed on the failure of a flap-operating rod due to metal fatigue, resulting in asymmetrical lift.
Accident
The Ambassador, construction number 5211,
had previously been British European Airways' ''Sir Francis Drake''. It had recently been converted to a "horsebox" transport and was on a flight from
Deauville, France, to Heathrow Airport. Flight C.6845 was transporting eight
racehorse
Horse racing is an equestrian performance sport, typically involving two or more horses ridden by jockeys (or sometimes driven without riders) over a set distance for competition. It is one of the most ancient of all sports, as its basic pr ...
s belonging to businessman
William Hill together with five grooms. As the aircraft was landing on Heathrow's runway 28R the left wing dropped, and the
wing tip
A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft.
Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of sha ...
and left
landing gear
Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...
touched the grass adjacent to the runway. The crew tried to increase power to
go-around
In aviation, a go-around is an aborted landing of an aircraft that is on final approach or has already touched down. A go-around can either be initiated by the pilot flying or requested by air traffic control for various reasons, such as an unstab ...
and climb away, but the
bank angle
A banked turn (or banking turn) is a turn or change of direction in which the vehicle banks or inclines, usually towards the inside of the turn. For a road or railroad this is usually due to the roadbed having a transverse down-slope towards the ...
increased. The aircraft hit two parked empty
British European Airways
British European Airways (BEA), formally British European Airways Corporation, was a British airline which existed from 1946 until 1974.
BEA operated to Europe, North Africa and the Middle East from airports around the United Kingdom. The a ...
Hawker Siddeley Trident
The Hawker Siddeley HS-121 Trident (originally the de Havilland DH.121 and briefly the Airco DH.121) is a British airliner produced by Hawker Siddeley.
In 1957, de Havilland proposed its DH.121 trijet design to a British European Airways (B ...
s, knocking the
tail fin off one (''G-ARPI'') and slicing off the entire
tail section of the other (''G-ARPT''). The Ambassador cartwheeled following the impact and slid upside down coming up against the ground floor of the terminal building where there was an explosion.
Six people on board the Ambassador died, including the flight crew and three of five
groom
A bridegroom (often shortened to groom) is a man who is about to be married or who is newlywed.
When marrying, the bridegroom's future spouse (if female) is usually referred to as the bride. A bridegroom is typically attended by a best man an ...
s, along with all eight horses. The other two grooms were seriously injured as were two people on the ground. A further 29 people on the ground received slight injuries.
Of the two Trident aircraft, G-ARPT was damaged beyond economic repair and G-ARPI was subsequently repaired. G-ARPI was involved in
an accident in 1972 resulting in the deaths of 118 people and becoming the deadliest non-terrorist aviation accident in the UK. A Viscount (G-APKF) received slight damage.
The Viscount was also repaired but later too involved in a fatal hull-loss accident in Cambodia as XW-TDN in 1975.
All other Ambassadors were grounded pending the result of an inquiry.
The starboard rod from the aircraft was tested and found satisfactory but rods from some other Ambassadors showed signs of cracking and when tested failed in a similar manner to G-AMAD's port rod. The rods on aircraft were strengthened and shown to be capable of 37,000 hours flight time.
Probable cause
The port (left)
flap
Flap may refer to:
Arts, entertainment, and media
* ''Flap'' (film), a 1970 American film
* Flap, a boss character in the arcade game ''Gaiapolis''
* Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland''
Biology and he ...
operating rod had failed due to
metal fatigue
In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striations on some parts o ...
. While the mechanism had failed, the compensating mechanism between the two sets of flaps remained intact. The port flaps had retracted but the compensator caused the starboard ones to extend further. The resulting asymmetry of lift resulted in the roll to port.
The pilot probably tried to overshoot and set the flaps to the correct 10 degrees, but due to the mechanism design this was not sufficient to cause the starboard flaps to retract (which would have taken 25 seconds in any event). The Department of Transport report concluded that whatever the pilot's actions, it was "doubtful" whether an accident could have been avoided.
After the accident all Ambassadors were fitted with steel reinforcements to the flap operating rods.
See also
*
List of accidents and incidents involving commercial aircraft
This list of accidents and incidents involving commercial aircraft includes notable events that have a corresponding Wikipedia article. Entries in this list involve passenger or cargo aircraft that are operating commercially and meet this list ...
*
Air Vanuatu Flight 241
On 28 July 2018, Air Vanuatu Flight 241, operated by ATR-72 registration YJ-AV71 suffered an in-flight engine fire while operating a domestic scheduled passenger flight from Whitegrass Airport, Tanna to Bauerfield International Airport, Port Vil ...
, in which an aircraft departed the runway and collided with two parked aircraft
*
British European Airways Flight 548
British European Airways Flight 548 was a scheduled passenger flight from London Heathrow to Brussels that crashed near Staines, Surrey, England, soon after take-off on 18 June 1972, killing all 118 people on board. The accident became known as ...
, Aviation incident in which G-ARPI was also involved
References
Further reading
* "Report on the Accident to Ambassador AS.57 Series 2, G-AMAD, at Heathrow Airport, London, on 3 July 1968". CAP 322,
HMSO
The Office of Public Sector Information (OPSI) is the body responsible for the operation of His Majesty's Stationery Office (HMSO) and of other public information services of the United Kingdom. The OPSI is part of the National Archives of the Un ...
"Ambassador accident cause detailed"''Flight International'' 1969.
External links
Photograph of severed tail section of Trident 1 G-ARPT– taken in 1972
*
ttp://www.airteamimages.com/hawker-siddeley-trident_G-ARPI_bea---british-european-airways_66991.html Photograph showing damage to tail of Trident 1C G-ARPITrident accidents and incidents* a 1969 ''Flight'' article
A short clip showing the accident of G-AMAD
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Aviation accidents and incidents in 1968
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1968 BKS Air Transport Heathrow crash
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