Before the beginning of the war, aerial reconnaissance was usually carried out by civilian Lufthansa planes equipped with cameras. This practice was continued throughout the war as long as civilian airlines remained operational; later on, recon missions were most often carried out by Junkers Ju 86s flying at very high altitudes or by flying boats. Due to the lack of German aircraft with sufficient range, some recon missions used captured American B-17s or B-24s and Soviet Tu-2s.