|Role||Escort Fighter/Ground Attack Aircraft|
|Primary user||Imperial German Army Air Service|
The Halberstadt CL.II was a German two seat escort fighter/ground attack aircraft of World War I. It served in large numbers with the German Luftstreitkräfte (Imperial German Army Air Service) in 1917-18.
Development and design 
Early in 1917, Idflieg, the German Army Inspectorate of Flying Troops, developed a requirement for a new type of two seat aircraft, smaller than the existing C-type aircraft. This type, to be known as CL-type aircraft, were to be used to equip Schutzstaffeln (Protection flights) to escort reconnaissance aircraft. To meet this requirement, Halberstadt developed an aircraft based on its earlier, unsuccessful Halberstadt D.IV single seat fighter. Originally designated the Halberstadt C.II, it was re-designated the Halberstadt CL.II when the CL designation was applied.
The CL.II was a single-engined biplane, with an all-wooden structure. The fuselage was covered with thin plywood panelling and housed the crew of two in a single cockpit, with the observer's 7.92 mm (.312 in) machine gun being mounted on an elevated gun ring, giving a good field of fire, allowing downwards fire at targets on the ground. The single-bay wings were fabric-covered, with a swept upper wing.
The CL.II passed its Typenprüfung (type-test) on 7 May 1917, which resulted in production orders being placed. Halberstadt built 700 CL.IIs by the time production shifted to the improved CL.IV in mid-1918. A further 200 CL.II aircraft were built in 1918 by the Bayerische Flugzeug-Werke (BFW).
Operational history 
The CL.II entered service in August 1917, and proved extremely successful, its excellent manoeuvrability, rate of climb and good field of fire for its armament allowing it to match opposing single-seat fighters. It also proved to be well suited to close-support, which became the primary role of the CL-type aircraft, the units operating them being re-designated Schlachtstaffelen (Battle flights).
Ground support by the Schlachtstaffeln proved very effective, being used both in support of German attacks and to disrupt enemy attacks. An early example of the successful use of CL type aircraft in the ground attack role was during the German counter attack on 30 November 1917 during the Battle of Cambrai, where they were a major factor in the German performance.
The success of the German tactics at Cambrai, including the use of close air support, resulted in the Germans assembling large numbers of CL-types in support of the Spring Offensive in March 1918, with 38 Schlachtstaffelen (equipped with the CL.II, CL.IV and the Hannover CL.III) available, of which 27 were deployed against the British forces during the initial attack Operation Michael The CL.II continued in service until the end of the War.
- Main production type, powered by Mercedes D.III engine of 110 kW (150 hp).
- CL.II fitted with BMW IIIa engine. Few produced for evaluation purposes.
- Lithuania (postwar)
- Poland (postwar)
Specifications (CL.II) 
Data from German Aircraft of the First World War 
- Crew: Two
- Length: 7.30 m (23 ft 11⅜ in)
- Wingspan: 10.77 m (35 ft 4 in)
- Height: 2.75 m (9 ft 0¼ in)
- Wing area: 27.5 m² (297 ft²)
- Empty weight: 773 kg (1,701 lb)
- Loaded weight: 1,133 kg (2,493 lb)
- Powerplant: 1 × Mercedes D.III 6-cylinder water cooled inline engine, 120 kW (160 hp)
- Maximum speed: 165 km/h (90 kn, 103 mph) at 5,000 m (16,400 ft)
- Service ceiling: 5,090 m (16,600 ft)
- Wing loading: 41.2 kg/m² (8.4 lb/ft²)
- Power/mass: 0.11 kW/kg (0.06 hp/lb)
- Endurance: 3 hr
- Climb to 1,000 m (3,280 ft): 5 min
- Climb to 5,000 m (16,400 ft): 39.5 min
- 1 ×× 7.92 mm (.312 in) LMG 08/15 "Spandau" machine gun, synchronized
- 1 × 7.92 mm (.312 in) Parabellum MG14 machine gun, on ring mount for observer
- Up to 5 × 10 kg (20 lb) bombs
See also 
- Related development
- Aircraft of comparable role, configuration and era
- Gray and Thetford 1961, p.xv.
- Gray and Thetford 1961, p.137.
- Green and Swanborough 1994, p.274.
- Gray and Thetford 1961, p.136.
- Gray and Thetford 1961, p.136-137.
- Gray and Thetford 1961, p.140-141.
- Gray and Thetford 1962, p.138-139
- Angelucci 1981, p.48
- Angelucci, Enzo (ed.). World Encyclopedia of Military Aircraft. London: Jane's, 1981. ISBN 0-7106-0148-4.
- Gray, Peter and Thetford, Owen. German Aircraft of the First World War. London: Putnam, 1962.
- Green, William and Swanborough, Gordon. The Complete Book of Fighters. New York: Smithmark, 1994. ISBN 0-8317-3939-8.