Yesterday, December 27th, marked the 30th anniversary of what went down in history as the miracle of Gottröra (in Swedish Miraklet i Gottröra) or the Gottröra crash (in Swedish Gottrörakraschen).
Scandinavian Airlines System passenger flight SK751 was a regularly scheduled flight from Stockholm, Sweden, to Warsaw, Poland, via Copenhagen, Denmark. 30 years ago, on 27th December 19991, 129 passengers and crew members survived an airplane crash that could have turned into a fatal tragedy. The aircraft in question was a McDonnell Douglas MD-81 fitted with two Pratt & Whitney JT8D low-bypass turbofan engines. The aircraft operated its first flight in March 1991, meaning that when the accident occured, the plane had been in service for just 9 months. The SAS MD-81 flight was piloted by Danish captain Stefan G. Rasmussen (44 years old) and Swedish first officer Ulf Cedermark (34 years old). Both of them were highly experienced pilots with 8,000 and 3,000 hours of flight respectively. Due to flight complications, the pilots were forced to make an emergency landing in a field near Gottröra, Sweden. Luckily, all 129 passengers and crew members survived the crash, with only 25 people injured — two of them seriously.
The cause of the accident
The cause of the accident was found to be the excessive accumulation of ice on the aircraft’s wings before takeoff. The ice formed on the wings’ inner roots and was then ingested into the plane’s engines as the aircraft took off, severely damaging both engines. The airplane had landed at Stockholm-Arlanda Airport the evening before the accident and was parked at temperatures of about 0 to 1 °C. Around 2,550 kg of very cold fuel remained in the wing tanks. Overnight, ice accumulated on the upper part of the wings, but was not detected during the deicing process. The airplane was de-iced using 850 litres of de-icing fluid; however, neither the de-icing personnel nor the captain pilot Rasmussen – as required to do by Scandinavian Airlines Policies – checked for remaining ice afterwards.
A short time after liftoff, the ice broke off and crystals of ice were drawn into the fans of the two engines, disturbing the airflow. The disturbed airflow made the compressors stall and, consequently, the engines surged and eventually broke up. The pilots started noticing noises and vibration of engine No. 2 after only 25 seconds of flight. Engine No. 1 surged about 39 seconds later. Both engines failed at 76 and 78 seconds, respectively, when the airplane was flying at an altitude of 3,220 ft. At that point, the pilots requested a return to Arlanda airport, but then they chose a field in the forest near Gottröra, Uppland, for an immediate emergency landing. During the emergency landing, the airplane hit several trees and lost a large part of the right wing and then slid across the field for 110 m. Fortunately, there were no fatalities and only 25 injuries, mainly thanks to the brace position adopted by passengers as instructed by the crew.
The flight crew and pilots were acclaimed for their skilled emergency landing that has saved dozens of lives. Captain Rasmussen declared to be proud of his crew. However, he decided not to pilot commercial aircrafts again. Still today, Scandinavian Airlines uses flight number SK751 for its Copenhagen-to-Warsaw route.