Investigation Summary
Flight 644 departed Buenos Aires at 07:31 local time under Instrument Flight Rules (IFR). Although weather reports indicated the presence of cumulonimbus clouds along the route, the crew and the airline's flight dispatcher proceeded with the flight at an altitude of 4,800 meters (15,700 feet). At 08:19, the crew reported bad weather and a delay in reaching the Azul waypoint; this was their final transmission. The investigation determined that the aircraft entered a region of violent turbulence with winds estimated at 76 knots. The resulting aerodynamic forces caused the structural failure and separation of the right wing. The aircraft then entered a terminal dive, impacting the ground at approximately 220 knots. A significant factor in the accident was the lack of weather radar on commercial aircraft and at local airports in Argentina at the time, which left the crew unable to accurately detect and avoid the most dangerous cells within the storm system.
Final Conclusions
The investigation concluded that the primary cause was the in-flight disintegration of the aircraft due to the rupture of the right wing under loads exceeding design specifications. These loads were encountered in a zone of extremely violent turbulence. Contributing factors included the misevaluation of weather forecasts by both the captain and the flight dispatcher, leading to the selection of an inappropriate flight altitude for the prevailing conditions.
Photographic Evidence (1)
Video Analysis
It DISINTEGRATED in mid-air: The WORST TRAGEDY in Argentine History — A detailed look at the structural failure of Aerolíneas Argentinas Flight 644, which lost a wing due to severe updrafts and turbulence in 1961.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
First Officer
Systems & Failure Modes
Right Wing Structure
Suffered a complete structural rupture and separation after being subjected to aerodynamic loads beyond its design limits during severe turbulence.
Weather Radar
The absence of this system on the aircraft prevented the crew from identifying and navigating around hazardous cumulonimbus cells.
Interesting Facts
- 01The accident remains the deadliest in the history of Aerolíneas Argentinas.
- 02At the time of the crash, no commercial aircraft or airports in Argentina were equipped with weather radar.
- 03The aircraft was originally named 'Presidente Peron' before being renamed 'General San Martin' in the mid-1950s.
- 04The estimated probability of the crew encountering a cumulonimbus cloud without radar was calculated at 31%.
- 05The aircraft's manufacturer serial number (MSN) was 43136/137.
Safety Actions & Advisories
Weather Radar Mandate
Argentine authorities recommended the mandatory installation of weather radars on all commercial aircraft operating in the country.
ATC Improvements
Recommendations were made to improve Air Traffic Control services to better assist aircraft in avoiding adverse weather.
Location
APPROXIMATE POSITION · AIRPORT LEVEL · Coordinates are the estimate published in the official investigation report. The ring shows the accuracy the record supports, not the point of impact.