ASN Aircraft accident Avro 691 Lancastrian C.3 G-AGWH Tupungato Mountain
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Status:Accident investigation report completed and information captured
Date:Saturday 2 August 1947
Type:Silhouette image of generic a691 model; specific model in this crash may look slightly different
Avro 691 Lancastrian C.3
Operator:British South American Airways - BSAA
Registration: G-AGWH
MSN: 1280
First flight: 1945
Total airframe hrs:1655
Engines: 4 Rolls-Royce Merlin
Crew:Fatalities: 5 / Occupants: 5
Passengers:Fatalities: 6 / Occupants: 6
Total:Fatalities: 11 / Occupants: 11
Aircraft damage: Destroyed
Aircraft fate: Written off (damaged beyond repair)
Location:Tupungato Mountain (   Argentina)
Crash site elevation: 4600 m (15092 feet) amsl
Phase: En route (ENR)
Nature:International Scheduled Passenger
Departure airport:Morón Air Base, BA (SADM), Argentina
Destination airport:Santiago-Los Cerrillos Airport (ULC/SCTI), Chile
The Avro 691 Lancastrian 3 passenger plane, G-AGWH, was completing the last leg from Buenos Aires, Argentina to Santiago, Chile of a flight that originated in London, U.K. The flight from London to Buenos Aires was carried out in a York aircraft and at Buenos Aires the customary transfer was made to a Lancastrian to facilitate the crossing of the Andes Mountains.
The flight plan was made out for the route Buenos Aires-Santiago via Mendoza. The amount of fuel carried was 1,380 gallons, giving an estimated duration of 6 hours and 30 minutes. The estimated time of the flight was 3 hours 45 minutes. By keeping to the
flight plan and arriving over Mendoza at 18,000 feet the distance of 526 nautical miles from Buenos Aires to Mendoza should have taken 3 hours 12 minutes. The remaining distance of 106 miles from Mendoza to Santiago should have taken 33 minutes at proposed height of 26,000 feet. The aircraft departed Buenos Aires at 13:46 hrs UTC. Last contact with the flight was at 17:41 when the Chilean Air Force radio operator at Santiago when the flight stated an ETA of 17:45, ending with "STENDEC". This was repeated twice when the radio operator queried the call since he did not understand "STENDEC". Investigators were not able to find out what the radio operator of G-AGWH meant by "STENDEC".

In 1998, two Argentine mountaineers climbing Mount Tupungato, about 50 miles (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). In 2000, an Argentine Army expedition found additional wreckage, including a propeller and wheels that appeared to have belong to G-AGWH.

Probable Cause:

During a scheduled passenger flight, collision with the mountain, when the crew started a descent before the expected position, in IMC conditions, due to an incorrect calculation of the navigation speed.

Contributing factors:
Pilot in command:
Probable lack of knowledge of the weather condition "Mountain Wave" and jet stream
Adoption of the Central or Direct Route with bad weather conditions.

Atmospheric disturbance known as Mountain Wave associated with a jet stream

Accident investigation:

Investigating agency: JIAAC Argentina
Status: Investigation completed
Accident number: 43/00
Download report: Final report


» U.K. AIB investigation report dated 22 December 1947
» The Civil Aircraft Registers of Great Britain
» Star Dust Falling / J.Rayner


Add your photo of this accident or aircraft

This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Morón Air Base, BA to Santiago-Los Cerrillos Airport as the crow flies is 1114 km (696 miles).
Accident location: Exact; as reported in the official accident report.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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