1947 BSAA Avro Lancastrian Star Dust accident

On 2 August 1947, Star Dust, a British South American Airways (BSAA) Avro Lancastrian airliner on a flight from Buenos Aires, Argentina, to Santiago, Chile, crashed into Mount Tupungato, in the Argentine Andes. An extensive search operation failed to locate the wreckage, despite covering the area of the crash site, and the fate of the aircraft and its occupants remained unknown for over 50 years, giving rise to various conspiracy theories about its disappearance.

BSAA Star Dust accident
BSAA Lancastrian 3 G-AGWH painted as Stardust
Accident
Date2 August 1947
SummaryControlled flight into terrain due to severe weather conditions[1][2]
SiteMount Tupungato, Argentina
33°22′15″S 69°45′40″W
Aircraft
Aircraft typeAvro Lancastrian
OperatorBritish South American Airways
RegistrationG-AGWH
Flight originMorón Airport, Buenos Aires, Argentina
DestinationLos Cerrillos Airport, Santiago, Chile
Passengers6
Crew5
Fatalities11
Survivors0

In the late 1990s, pieces of wreckage from the missing aircraft began to emerge from the glacial ice. It is now believed that the crew became confused as to their exact location while flying at high altitudes through the (then poorly understood) jet stream. Mistakenly believing they had already cleared the mountain tops, they started their descent when they were in fact still behind cloud-covered peaks, and Star Dust crashed into Mount Tupungato, killing all aboard and burying itself in snow and ice.[1][2]

The last word in Star Dust's final Morse code transmission to Santiago airport, "STENDEC", was received by the airport control tower four minutes before its planned landing and repeated twice; it has never been satisfactorily explained.

Background

The aircraft, an Avro 691 Lancastrian 3, was built as constructor's number 1280 for the Ministry of Supply to carry 13 passengers, and first flew on 27 November 1945. Its civil certificate of airworthiness (CofA) number 7282 was issued on 1 January 1946. It was delivered to BSAA on 12 January 1946, was registered on 16 January as G-AGWH and given the individual aircraft name "Star Dust".[3]

Star Dust carried six passengers and a crew of five on its final flight. The captain, Reginald Cook, was an experienced Royal Air Force pilot with combat experience during World War II—as were his first officer, Norman Hilton Cook, and second officer, Donald Checklin. Reginald Cook had been awarded the Distinguished Service Order (DSO) and the Distinguished Flying Cross (DFC). The radio operator, Dennis Harmer, also had a record of wartime as well as civilian service.

Star Dust's last flight was the final leg of BSAA Flight CS59, which had started in London on an Avro York named Star Mist on 29 July 1947, landing in Buenos Aires on 1 August.[4] Marta Limpert was the only one of the six passengers known for certain to have initially boarded Star Mist in London[5] before changing aircraft in Buenos Aires to continue on to Santiago with the other passengers.[6]

Disappearance

Mount Tupungato seen from the air

Star Dust left Buenos Aires at 1:46 PM on 2 August[7] and was apparently uneventful until the radio operator (Harmer) sent a routine message in Morse code to the airport in Santiago at 5:41 PM, announcing an expected arrival of 5:45 PM.[8] However, Star Dust never arrived, no more radio transmissions were received by the airport, and intensive efforts by both Chilean and Argentine search teams, as well as by other BSAA pilots, failed to uncover any trace of the aircraft or of the people on board.[9] The head of BSAA, Air Vice Marshal Don Bennett, personally directed an unsuccessful five-day search.[10]

A report by an amateur radio operator who claimed to have received a faint SOS signal from Star Dust initially raised hopes that there might have been survivors,[9] but all subsequent attempts over the years to find the vanished aircraft failed. In the absence of any hard evidence, numerous theories arose —including rumours of sabotage (compounded by the later disappearance of two other aircraft also belonging to British South American Airways);[11] speculation that Star Dust might have been blown up to destroy diplomatic documents being carried by a passenger;[11] or even the suggestion that Star Dust might have been taken or destroyed by a UFO (an idea fuelled by unresolved questions about the flight's final Morse code message).[8]

Discovery of wreckage and reconstruction of the crash

A main wheel from the Star Dust, found amidst the wreckage in 2000

In 1998, two Argentine mountaineers climbing Mount Tupungato—about 60 mi (100 km) west-southwest of Mendoza City, and about 50 mi (80 km) east of Santiago—found the wreckage of a Rolls-Royce Merlin aircraft engine, along with twisted pieces of metal and shreds of clothing, in the Tupungato Glacier at an elevation of 15,000 ft (4,600 m).[9]

In 2000, an Argentine Army expedition found additional wreckage—including a propeller and wheels (one of which had an intact and inflated tyre)—and noted that the wreckage was well localised, a fact which pointed to a head-on impact with the ground, and which also ruled out a mid-air explosion.[12] Human remains were also recovered, including three torsos, a foot in an ankle boot and a manicured hand. By 2002, the bodies of five of the eight British victims had been identified through DNA testing.[13]

A recovered propeller showed that the engine had been running at near-cruising speed at the time of the impact. Additionally, the condition of the wheels proved that the undercarriage was still retracted, suggesting controlled flight into terrain rather than an attempted emergency landing.[14] During the final portion of Star Dust's flight, heavy clouds would have blocked visibility of the ground. It has therefore been suggested that, in the absence of visual sightings of the ground due to the clouds, a large navigational error could have been made as the aircraft flew through the jet stream—a phenomenon not well understood in 1947, in which high-altitude winds can blow at high speed in directions different from those of winds observed at ground level.[15] If the airliner, which had to cross the Andes mountain range at 24,000 feet (7,300 m), had entered the jet-stream zone—which in this area normally blows from the west and south-west, resulting in the aircraft encountering a headwind—this would have significantly decreased the aircraft's ground speed.

Mistakenly assuming their ground speed to be faster than it really was, the crew may have deduced that they had already safely crossed the Andes, and so commenced their descent to Santiago, whereas in fact they were still a considerable distance to the east-north-east and were approaching the cloud-shrouded Tupungato Glacier at high speed.[11] Some BSAA pilots, however, have expressed scepticism at this theory; convinced that Cook would not have started his descent without a positive indication that he had crossed the mountains, they have suggested that strong winds may have brought down the craft in some other way.[16] One of the pilots recalled that "we had all been warned not to enter cloud over the mountains as the turbulence and icing posed too great a threat."[10]

A set of events similar to those that doomed Star Dust also caused the crash of Uruguayan Air Force Flight 571 in 1972 (depicted in the film Alive), though there were survivors from that crash because it involved a glancing blow to a mountainside rather than a head-on collision.[17]

Star Dust is likely to have flown into a nearly vertical snow field near the top of the glacier, causing an avalanche that buried the wreckage within seconds and concealed it from searchers. As the compressed snow turned to ice, the wreckage would have been incorporated into the body of the glacier, with fragments emerging many years later and much farther down the mountain. Between 1998 and 2000, about ten per cent of the total expected wreckage emerged from the glacier, prompting several re-examinations of the accident. More debris is expected to emerge in future, not only as a result of normal glacial motion, but also as the glacier melts.[11]

A 2000 Argentine Air Force investigation cleared Captain Cook of any blame, concluding that the crash had resulted from "a heavy snowstorm" and "very cloudy weather", as a result of which the crew "were unable to correct their positioning".[1][2]

STENDEC

The last Morse code message sent by Star Dust was "ETA SANTIAGO 17.45 HRS STENDEC".[8] The Chilean Air Force radio operator at the Santiago airport described this transmission as coming in "loud and clear" but very fast; as he did not recognise the last word, he requested clarification and heard "STENDEC" repeated twice in succession before contact with the aircraft was lost.[18][19] This word has not been definitively explained and has given rise to much speculation.[8]

The staff of the BBC television series Horizon—which presented an episode in 2000 on the Star Dust disappearance—received hundreds of messages from viewers proposing explanations of STENDEC. These included suggestions that the radio operator, possibly suffering from hypoxia, had scrambled the word DESCENT (of which STENDEC is an anagram); that STENDEC may have been the initials of some obscure phrase or that the airport radio operator had misheard the Morse code transmission despite it reportedly having been repeated multiple times. The Horizon staff concluded that, with the possible exception of some misunderstanding based on Morse code, none of these proposed solutions was plausible.[8] It has also been suggested that WWII pilots used this seemingly obscure abbreviation when an aircraft was in hazardous weather and was likely to crash, meaning "Severe Turbulence Encountered, Now Descending Emergency Crash-landing".[20] It is also known that all the crew including the flight attendant had prior WWII air service experience. However, this theory does not match with the rest of the message, which was reporting the flight's estimated arrival time.

The simplest explanation put forward to date is that the spacing of the rapidly sent message was misheard or sloppily sent. In Morse code, determining accurate spacing between characters is vital to properly interpret the message; STENDEC uses exactly the same dot/dash sequence as SCTI AR (airport code, "over").[21] SCTI AR is a transmission that would have been expected to occur in the given context.

Alternatively, the Morse spelling for STENDEC is one character off from instead spelling VALP, the call sign for the airport at Valparaiso, some 110 kilometers north of Santiago.[22]

gollark: I don't think it actually has that much effect on the lower level functioning of the civil service etc.
gollark: Infrastructure projects run over budget and over time all the time for no apparent reason.
gollark: I don't mean the cabinet, I mean the rest of the government and large companies.
gollark: It seems like regardless of how you pick the leaders and whatever, big organisations just operate increasingly badly over time/scale.
gollark: In any case, I don't even know if there's any way to get stable, fair and actually competent large-scale governance at this point.

See also

Notes

  1. "Crash pilot cleared 50 years on". The Guardian. 7 July 2000. Archived from the original on 13 March 2016. Retrieved 28 September 2011.
  2. "Pilot finally cleared over mystery of 1947 mountain plane disaster". The Birmingham Post. 8 July 2000. Archived from the original on 24 October 2012. Retrieved 18 August 2011.
  3. Ottaway, Susan; Ottaway, Ian (2007). "Aircraft operated by British South American Airways". FLY WITH THE STARS, a history of British South American Airways. Speedman Press Limited. ISBN 978-0-7509-4448-9.
  4. Rayner (2002), pp. 119–122.
  5. Rayner (2002), p. 119.
  6. "Vanished: 1947 Official Accident Report". pbs.org. PBS. Archived from the original on 23 May 2012. Retrieved 18 August 2011.
  7. Rayner (2002), p. 124.
  8. "'STENDEC' – Stardust's final mysterious message". BBC. 2 November 2000. Archived from the original on 20 January 2012. Retrieved 18 August 2011.
  9. "Stardust Lost in the Andes". Vanishings!. 27 September 2003. History International.
  10. Jackson, Archie (1997). Can Anyone See Bermuda? Memories of an Airline Pilot (1941–1976). Gillingham, Dorset: Cirrus Associates. p. 75. ISBN 0-9515598-5-0.
  11. "Vanished: The Plane That Disappeared". BBC. 2 November 2000. Archived from the original on 21 January 2011. Retrieved 18 August 2011.
  12. Rayner (2002), p. 212.
  13. "DNA clues reveal 55-year-old secrets behind crash of the Star Dust". The Guardian. 6 September 2002. Archived from the original on 26 August 2013. Retrieved 18 August 2011.
  14. Rayner (2002), p. 213.
  15. Rayner (2002), p. 214.
  16. Rayner (2002), pp. 215–216.
  17. "I Am Alive: The Crash of Uruguayan Air Force Flight 571". History.com. Archived from the original on 5 October 2012. Retrieved 18 August 2011.
  18. Ministry of Civil Aviation (1948), Ministry of Civil Aviation, Civil Aircraft Accident: Report on the accident to Lancastrian III G-AGWH which occurred on 2nd August 1947 in the Andes Mountains South America (Accidents Investigation Branch Report No. C.A. 106) (PDF), London: His Majesty's Stationery Office, archived from the original (PDF) on 10 August 2014, retrieved 7 January 2013
  19. Rayner (2002), p. 125.
  20. Bowcott, Owen (6 September 2002). "DNA clues reveal 55-year-old secrets behind crash of the Star Dust". The Guardian. Archived from the original on 6 January 2017. Retrieved 16 December 2016.
  21. SAR Technology – Aviation Cold Case Response, archived from the original on 29 September 2018, retrieved 3 December 2018
  22. "Archived copy" (PDF). Archived (PDF) from the original on 2 January 2019. Retrieved 11 June 2019.CS1 maint: archived copy as title (link)

References

  • Rayner, Jay (2002). Star Dust Falling: The Story of the Plane that Vanished. Doubleday. ISBN 0-385-60226-X.
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