Today marks 27 years since the deadliest aviation accident ever to occur in the country of El Salvador. On August 9th, 1995, a Boeing 737 flown by former Guatemalan regional carrier Aviateca collided with the nation's second-highest volcano, resulting in the death of everyone on board. Let's take a look at how it happened.

The flight and aircraft involved

Aviateca flight 901 was an evening service that originated at Guatemala City's La Aurora International Airport (GUA), which served as the airline's main hub. Meanwhile, its destination was El Salvador International Airport (SAL). Pre-COVID, this facility was Central America's third-busiest airport by passenger numbers, and it serves the country's eponymous capital and largest city, San Salvador.

Guatemala City-San Salvador remains a busy Central American corridor today, with three carriers present on the route. These are Avianca, Transportes Aéreos Guatemaltecos, and Volaris El Salvador. In its later years, Aviateca became Avianca Guatemala, before eventually being absorbed into Avianca's mainline operations.

According to the Aviation Safety Network, Aviateca flight 901 was operated by a Boeing 737-200 registered as N125GU on August 9th, 1995. The aircraft, which was just under eight years old at the time, had 65 people onboard, with this figure comprising 58 passengers and seven crew members. Its full route was Miami-Guatemala City-San Salvador-Managua-San Jose.

Aviateca Boeing 737 parked on apron
N125GU began its career with Malaysia Airlines, before joining Aviateca in 1993. Photo: Simon Butler via Flickr

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Confusion on approach

While the flight's first leg from Miami to Guatemala City passed without incident, tragedy sadly struck on the San Salvador-bound sector. Difficulties began to arise on the flight's approach into San Salvador, where it had to contend with challenging weather conditions in the form of a thunderstorm and heavy precipitation.

As such, the flight was instructed by air traffic control to deviate from its present course in order to avoid the area of adverse weather. The plan was for it to overfly the airport before turning to make an Instrument Landing System approach towards its 3,200-meter-long runway 07. However, things took a turn for the worse.

Specifically, confusion between the pilots and air traffic control regarding the aircraft's location at the time the instructions were given led to a catastrophic mistake. ATC had cleared the aircraft to fly at 5,000 feet, but this ended up putting it on a collision course with San Vicente, a volcano that peaks at 7,159 feet.

San_vicente_els
San Vicente's last significant eruption is said to have taken place over 1,700 years ago. Photo: Kristal Dorion/US Geological Survey via Wikimedia Commons

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Deadly collision

By this time, tragedy was inevitable. As the flight neared the stratovolcano, its pilots were alerted to its terrain by the 737's Ground Proximity Warning System (GPWS). This prompted them to increase thrust and altitude, but their actions were ultimately in vain. At 20:14 local time, Aviateca flight 901 collided with San Vicente, with the impact and explosion subsequently killing everyone onboard.

The 65-person death toll rendered the crash the deadliest ever to occur in El Salvador. The country's civil aviation regulators, the Dirección General De Transporte Aéreo, investigated the accident, and found that the confusion between the captain and the ATC regarding the plane's location had been a key factor.

Interestingly, the authorities also highlighted poor crew resource management at Aviateca as part of their findings. Specifically, their report noted that the first officer was unable to assertively put forward concerns about the flight's position. With better communication in all areas, the outcome could have been rather different.

Source: Aviation Safety Network