The Air Force order of battle comprised the 1st, 2nd, 3rd and 4th Army Aviation Orlyaks (Army Air Groups or air regiments), each attached to the correspondingly-numbered field army. Each orlyak had a fighter, a line bomber and two reconnaissance (squadrons). There was also an Independent Aviation corps, which combined the 5th Bomber and 6th Fighter Regiments. The training units consisted of the "Junker" School Orlyak at Vrazhdebna airfield, the 2nd Training Orlyak at Telish airfield (called the Blind Flying Training School) and the 3rd Training Orlyak at Stara Zagora airfield. In 1940, the Bulgarian aviation industry provided the air force with 42 DAR 9 Siniger and 45 Kaproni-Bulgarski KB-5 Chuchuliga aircraft, along with preparing for serial production of the KB-6 – Bulgaria's first twin-engined aircraft. At year's end, the Bulgarians had 595 aircraft (of which 258 were combat aircraft) and 10,287 personnel.