The SK-1-M ejector seat was installed in the F-13, PF and U versions of the MiG-21 family. When ejecting, the cabin cover and the seat acted as a sort of pod protecting the pilot from the dangers of high pressure air flow. After the ejection the cabin cover dropped away and the parachute opened bringing the pilot safely down. Since this method proved to be dangerous in low altitude ejections, it was modified for later versions of the MiG-21. Of the 80 F-13 models introduced in Hungary 30 were destroyed causing 12 fatalities. Of the 12 training U-400s, 1 was destroyed causing 2 deaths. 6 U-600 planes were destroyed with 2 lives lost. Of the 24 PFs 7 were destroyed at the cost of 2 lives.