"Ночные ласточки" aka Notchnye Lastotchki (Night Swallows) is a Russian dramatic series about a group of Soviet women pilots who flew night harassment flights against the German Army during World War Two. During WW2, the Soviet Air force used female pilots to man obsolete PO-2 biplane trainers. These aircraft were first produced in 1928 and could only carry about 600 pounds of light bombs. They flew low level night time missions that were effective at depriving German troops of sleep etc. The German called the pilots "Night Witches". The Germans soon had their own version of these night harassment squadrons.