The A.E.G. C.IV was the most numerous entry in the A.E.G. C series, and introduced a fixed forward firing machine gun and a more powerful engine.
The C series began with the C.I of March 1915, itself an armed version of the B.II. The C.I was a two bay biplane, with a welded steel fuselage, wooden wing ribs and a fabric covering, and armed with a flexibly mounted machine gun in the observer's position. It was followed by the C.II, which was slightly smaller and lighter, and thus more manoeuvrable.
The C.IV was produced at a time when the German air service was looking to expand the number of reconnaissance units it was operating as quickly as possible.
Early in 1916 the C.II struggled to pass its structural tests. One aircraft was then used to test a number of improvements to the design, with the progressive designations C.IIa to C.IIe.
The C.IV was a similar design to the C.II, although slightly larger in size. It was given a 160hp Mercedes D.III engine, which was mounted in a rather ugly configuration with most of the engine exposed above the fuselage and a horn like exhaust rising above the height of the upper wing. The engine was really too large for the aircraft.
The C.IV kept the flexibly mounted observer's machine gun of the C.I and C.II but also added a fixed forward firing LMG 08/15 machine gun.
It used the same construction methods as the earlier aircraft, with a welded steel tube structure, wooden wing ribs and fabric covering. Some effort went into simplifying the air frame.
The main fuselage was a rectangular box, with 16m steel tube for the longerons and most transverse tubes, and 20mm steel tube for the last three sets of transverse tubes. The fuselage was made stronger, as the C.II had almost been too heavy for the structure. A number of welding jigs were produced, allowing women and semi-skilled workers to work on the framework. The attention to detail was impressive and the quality of the welding on captured examples impressed the British.
The wings used 40mm steel tube spars. The wings on earlier entries in the series were designed to be foldable for road transport, but this was eliminated on the C.IV. The ailerons used the same steel tube construction, and were unbalanced. The centre section of the upper wing was supported by six steel struts, as it carried a heavy radiator and a gravity fuel tank.
The C.IV was a very robust aircraft, and could survive a fair amount of battle damage.
The C.IV had a three-position variable incidence tailplane that could only be adjusted on the ground.
The prototype made its maiden flight in March 1916. A contract for 100 aircraft was placed in the same month, but the wing spar failed static load tests in June 1916, delaying the acceptance of the type. It finally reached the front in October 1916.
Around 400 C.IVs were produced, from a total of 658 C series aircraft built by A.E.G. These were ordered in seven batches - four batches of 100 aircraft were ordered in March 1916, October 1916, April 1917 and May 1917. This was followed by three orders for tropical aircraft, starting with one for 75 aircraft in July1917, and then two smaller orders - one for 8 aircraft in December 1917 and another for 12 in February 1918.
The aircraft was built also built under licence by Fokker, much to the irritation of Anthony Fokker himself. Amongst the Fokker machines was the A.E.G. C.IV (Fok), produced for use with the training schools. A contract for 200 machines was placed in January 1917 and the first aircraft was tested at Aldershof in August 1917. A total of 39 problems were found, typical of Fokker production at this stage of the war, but after modifications the type was accepted for training use. Another 200 aircraft were ordered in June 1917 as the A.E.G. C.IVa (Fok), powered by the less effective 180hp Argus As.III engine. 100 of these aircraft were delivered between November 1917 and April 1918 and the rest of the order was then cancelled after Fokker finally produced some high quality designs of his own, the Fokker Dr.I and Fokker D.VII.
It saw service on most fronts from its appearance almost to the end of the war. The C.IV was popular in service because of its reliability and good handling in the air, although it was more difficult to land and required more skill to fly than the Albatros C.III or DFW C.V. It was normally deployed in small numbers in units that also had other aircraft types.
A number of modified aircraft, with larger radiators, were used by German and Turkish units in Palestine and Mesopotamia. The robust metal framework meant that the aircraft was seen as being suitable for the rough conditions of the desert, where wooden frames were more vulnerable, but it also meant that the aircraft was much harder to maintain. Any problems with the framework meant that the aircraft either had to be abandoned, or somehow manhandled back to the nearest welding equipment.
170 A.E.G. C types were in service in June 1917 across all fronts, the most in service at any one time and 40 were still in service in August 1918.
The C.IVa was a single prototype produced to enter the C-Type Competition held in the spring of 1918. It was powered by a 200hp Benz Bz.IVü engine, and made tests flights on 27 March and 5 April 1918. It was unable to reach an altitude of 5,000m, and was thus eliminated from the contest.
The C.IV N was an experimental night bomber version of the C.IV developed at the end of 1916. It had an increased wingspan of 50ft 2 3/8in with three bays instead of two and used a 150hp Benz Bz.III engine. It could carry six 110lb bombs. Only one example was built.
The A.E.G. C.V, with a 220hp engine, was outperformed by the Albatros C.V, and didn't enter production.
Engine: Mercedes D.III
Span: 44ft 1.5in
Length: 23ft 5.5in
Height: 10ft 11.75in
Empty weight: 1,764lb
Maximum take-off weight: 2,469lb
Max speed: 98mph
Climb Rate: 6min to 3,280ft
Service ceiling: 16,400ft
Endurance: 4 hours
Armament: One fixed forward firing 0.31in LMG 08/15 machine gun, one flexibly mounted 0.31in Parabellum machine gun
Bomb load: up to 200lb in observer's cockpit.