Scandinavian Airlines Flight 751 - Accident

Accident

The aircraft had arrived from Zürich on the previous evening and was parked overnight at temperatures of around 0 to 1 °C. About 2550 kg of flight-chilled very cold fuel remained in the wing tanks. Because of this, clear ice had formed on the upper side of the wings, but was not detected. The aircraft was de-iced with 850 liters of de-icing fluid, but not checked afterwards for remaining ice by either the de-icing personnel or the captain.

At lift-off and rapidly after it, pieces of ice slammed onto the fans of both engines, deforming the fan blades sufficiently to disturb the airflow to the compressors. The disturbed airflow caused the compressors to stall and this in turn caused engine surge. Because the engines were not throttled down sufficiently, the surges continued. The high loads from repeated engine surges quickly led to the breakup of both engines.

The airliner was piloted by Danish captain Stefan G. Rasmussen and Swedish first officer Ulf Cedermark. It was headed to Warsaw, Poland through Copenhagen, Denmark.

From the pilot's point of view, after 25 seconds of flight, noise, bangs and vibrations caused by no. 2 engine being in surge were first noticed. The flight crew responded by throttling down a little, but an automatic system (ATR, Automatic Thrust Restoration) that had not been described to the flight crew by the Scandinavian Airlines System (SAS), simultaneously increased throttle as a response to increasing altitude. As a consequence, the engine surges continued. An SAS flight captain, Per Holmberg, who was on board as a passenger, noticed the problems early and hurried to the cockpit to assist the crew. Engine no. 1 surged 39 seconds later, and both engines failed at 76 and 78 seconds into flight, at an altitude of 980 meters.

The pilot responded to the loss of both engines by pitching the aircraft down in a dive before leveling it, to try and have the aircraft glide the longest possible distance without stalling. The pilots requested a return to Arlanda and attempted the restart procedure, but with the plane breaking through the cloud cover at 270 meters the pilot chose a field in the forest, near Vängsjöbergs säteri in Gottröra, Uppland, for an immediate emergency landing.

During the final descent the plane hit some trees, losing a large part of the right wing. It impacted the ground tail-first, sliding along the field for 110 m, breaking into three parts before coming to a stop. Twenty-five people were injured, two of them seriously, but there were no fatalities. One of the reasons for the lack of fatalities was said to be the brace position that had been instructed by the flight stewardesses.

The flight crew, and especially Captain Rasmussen, were lauded for the skilled emergency landing in a fast-developing, potentially fatal situation. Rasmussen commented that "few civilian air pilots are ever put to a test of the skills they have acquired during training to this degree" and said he was proud of his crew and very relieved everyone had survived. He chose not to return to piloting commercial aircraft.