J.Herris Gotha Aircraft of WWI (A Centennial Perspective on Great War Airplanes 6)

Gotha G.VII/GL.VII

   Ordered on 15 March 1917, before daylight operations by Gotha G.LV aircraft had begun over the UK, four prototypes were built. These were designated Gs.I by Gotha and G.VII and G.VIII by Idflieg. The first prototype, Gotha GL.VII 550/17, was completed in September 1917, the month that Kagohl 3 transitioned to night bombing of the UK due to strengthened British defenses and increasing losses of Gotha G.IV bombers on daylight missions.
   The single-bay Gotha GL.VII 550/17, powered by two 260 hp Mercedes D.IVa engines, was one of four prototypes (G.550-553/17) ordered at the same time to explore different engine and wing configurations to determine the optimum layout to meet the demanding Idflieg requirements. A characteristic of the design was the close spacing of the engines to minimize asymmetric thrust with one engine out. This configuration was based on a patent by Ingenieur Michael Schlieffer, a Gotha pilot, and used the venturi effect between the nacelle and fuselage to minimize drag and help counter asymmetric thrust. The close engine spacing required a short nose that precluded a forward gunner.
   The next prototype, Gotha G.VII 551/17, had a longer, two-bay wing cellule. The Gotha G.VII was faster than the Albatros D.III but, despite months of intensive testing to optimize engine, airframe, and propeller configurations to maximize speed, climb, and ceiling, the desired performance was not achieved. In late 1918 engines with experimental centrifugal superchargers were installed in this machine for testing.
   The production standard GL.VII had a two-bay wing cellule with aerodynamically balanced ailerons on the upper wing and a box (biplane) tail. In 1918 eight aircraft were produced from an order for 55 aircraft (G.300-354/18). Gotha GL.VII 300/18 was the first of these and was powered by two Maybach Mb.IVa engines. It was sent to the front for evaluation in May 1918. GL.VII 302/18 went to the front on 27 June, followed by 301/18 on 1 August and 304/18 on 26 October. However, no further information is available on the evaluation of these aircraft and it is not known if they flew any operational sorties.
   Owing to promising results obtained in early Gotha tests, both Aviatik and LVG were awarded contracts in February 1918 to build the Gotha G.VII under license. Aviatik built 30 G.VII aircraft (G.100-129/18), few of which were handed over to the Allies after the war. Aviatik-built Gotha G.VII(Av) 112/18 was experimentally fitted with nose radiators for flight trials.

Gotha G.VII/GL.VII Specifications
Engines: 2 x 260 hp Mercedes D.IVa
Wing: Span 19.27 m
General: Length 9.60 m
Empty Weight 2420 kg
Loaded Weight 3140 kg
Maximum Speed: 180 km/h
Service Ceiling: 6000 m


Gotha G.VIII/GL.VIII

   Intended for high-speed day bombing, the Gotha GL.VII was fitted with an enlarged, three-bay wing to improve climb and ceiling. One fixed, forward-firing machine gun was fitted for the pilot, and the gunner had both dorsal and ventral flexible guns for defense.
   The Gotha GL.VIII prototype, G.VIII 552/17, was powered by Mercedes D.IVa engines, but the production standard was the over-compressed 260 hp Maybach Mb.IVa for more power at high altitude. All control surfaces were aerodynamically balanced and the biplane tail was retained for improved control with one engine out. The PuW bombs were carried externally under the fuselage.
   Gotha GL.VIII 307/18, powered by two 260 hp Maybach Mb.IVa engines, was sent to the Doberitz test center on 19 October 1918. The upper ailerons were fitted with Flettner servo controls for lighter control forces. According to an Idflieg appreciation, the performance of these aircraft "lagged far behind expectations." On the other hand, the war ended before sufficient experience was gathered to evaluate the aircraft adequately under combat conditions.

Gotha G.VIII/GL.VIII Specifications
Engines: 2 x 260 hp Maybach Mb.IVa
Wing: Span 21.73 m
Chord 2.05 m
Gap 2.00 m
General: Length 9.79 m
Useful Load 1030 kg
Loaded Weight 3706 kg
Maximum Speed: 180 km/h
Service Ceiling: 6000 m


Gotha GL-Type Production Summary
Manufacturer Type Qty Serials Notes
Gotha G.VII & G.VIII 4 550/17-553/17 Prototypes,- all 4 completed.
Gotha G.VII & G.VIII 55 300/18-354/18 Production aircraft; only 8 were completed.
Aviatik G.VII(Av) 100 100/18- 129/18* At least 30 completed.
LVG G.VII( LVG) 30 200/18-229/18 Reconnaissance aircraft. All 30 believed to have been completed.
Notes: *Rest of serials unknown.

M.Dusing German Aviation Industry in WWI. Volume 1 (A Centennial Perspective on Great War Airplanes 84)

Automobil und Aviatik A.-G., Leipzig-Heiterblick (Av)

Aircraft Development:

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  About 30 large Go.VII(Av) aircraft were built under license from Gotha in 1918.
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P.Grosz, G.Haddow, P.Shiemer Austro-Hungarian Army Aircraft of World War One (Flying Machines)

Gotha G.V and G.VII

  Idflieg offered the LFT five surplus Gotha G.V and 30 Gotha G.VII twin-engined bombers, less engines, as dual-control trainers in August 1918. Perhaps unknown to the LFT was the fact that, after much experimentation, the Gotha G.VII bomber proved a disappointing failure because it was unable to reach the specified operational altitude of 6000 meters (19,685 ft). This made it unsuitable for the day bomber and long-range reconnaissance role for which it had been designed. Uzelac declined the offer on grounds of "the poor service record experienced with the 40 Gotha G.IV(LVG) bombers in spite of having reinforced the airframe."

Журнал Flight

Flight, September 11, 1919.

AVIATIK "MILESTONES"

   In addition to their single-seaters and two-seaters, the Aviatik firm have also built several large machines (Riesenflugzeug), illustrations of three of which are published herewith.

The Aviatik, Type Go. G VII
   built in 1918, is a twin-engined machine of the bomber type. It was fitted with two 200 h.p. Benz engines placed on the wings in short engine nacelles. The radiators were in the nose of these nacelles. From the photograph it will be noticed that the two engine nacelles are placed comparatively close to the main fuselage, the nose of which is very short, allowing the tractor airscrew blades to pass in front of it. This arrangement of the engines has brought about a somewhat unusual strutting arrangement, as regards the inner cellule, at any rate. The tail is of the biplane type, with three rudders.