On May 18, 2011, Sol Líneas Aéreas Flight 5428 was a passenger flight that crashed near Los Menucos, Argentina killing all 22 people onboard. The aircraft involved was a Saab 340, operating a regular domestic service between Presidente Perón International Airport (NQN) in Neuquén and General Enrique Mosconi International Airport (CRD) in Comodoro Rivadavia.Before we get into the crash, let's first look at the Saab 340 and the airline operating the deadly flight. During the 1970s, Swedish military planemaker Saab became interested in the civilian aircraft market. The Saab 340 was a Swedish-built twin-engine turboprop typically configured to carry 34 passengers.

Sol Líneas Aéreas ceased operating in 2016

Founded in 2005, SOL S.A. Líneas Aéreas was an Argentine airline owned by the Transatlántica Group and the government of Santa Fe Province. The airline was created to improve air connections between the cities of Córdoba and Santa Fe. Headquarters in Rosario, the airline filed for bankruptcy and stopped flying in January 2016.

Sol Líneas Aéreas Flight 5428 was a regularly scheduled flight between Rosario – Islas Malvinas International Airport (ROS) and Enrique Mosconi International Airport (CRD) in Comodora Rivadavia with stops in Córdoba and Neuquén.

The plane was on the final leg of its journey

While taking off from International Airport in Neuquén at 20:05 local time for the final leg of the journey, the aircraft climbed to 19,000 feet. After being airborne for 24 minutes, the pilot leveled off at 17,800 feet, and the plane began to accumulate ice. The copilot radioed air traffic control (ATC) to ask permission to descend to a lower altitude.

This was granted with the plane being told to descend to 14,000 feet. While descending, the crew can be heard talking about how much ice was building up on the windscreen and wings. By the time the aircraft got down to 14,000, the icing conditions were severe. The plane continued on its flight path for two minutes until the airspeed dropped and the aircraft stalled. The pilots tried to regain control of the aircraft but failed, leaving the plane to crash into the ground and burn. Of the three crew members and 19 passengers, no one survived.

The investigation

Two days after the crash the aircraft's flight recorders were recovered and given to the Argentinian Junta de Investigaciones de Accidentes de Aviación Civil (JIAAC). They subsequently opened an investigation into the crash and issued a preliminary report in September of the same year. In the report, it stated that the accident was caused by a build-up of ice on the wings, causing the aircraft to stall and crash.

In its final report published in March 2015, the JIAAC said that it had confirmed its initial thoughts and that severe icing had overwhelmed the plane's de-icing systems.

The report also noted that the weather reports the crew had received for the day only mentioned the possibility of minor icing, and thus they were not prepared for the conditions. The report also called for Sol Líneas Aéreas pilots to receive more training in recovering from a stall.