The earlier G.II paved the way for the larger and more powerful G.III, which entered service in early 1917. While it looked somewhat similar to the G.II, the G.III was longer and had a greater wingspan which caused its designers to increase the number of interplane struts to three pairs on each side of the fuselage. Operational experience with the G.II had revealed a tendency for the aircraft to "nose over" during landings with deadly consequences for the nose gunner and possibly also the pilot. Friedrichshafen engineers solved this problem by equipping the G.III with an auxiliary wheel mounted under the nose gunner's position. The G.III also used the more powerful six-cylinder 190 kW Mercedes D.IVa engines. The extra power increased the bomb carrying capability enabling the aircraft to carry a bomb load of up to 1,000 kg, though this severely reduced operational range. In practice, the heaviest bomb load rarely exceeded 600 kg. Some of the bomb load could be carried internally but most of it was carried on removable external bomb-racks and usually consisted of streamlined P.u.W bombs but specialized munitions such as air-mines could also be carried. As production continued modifications were made to the G.III series that resulted in further two sub-variants:
Variants
The Friedrichshafen G.III series was ordered in large numbers from Friedrichshafen, Daimler and Hanseatische Flugzeug Werke and most of these aircraft were delivered before the war ended. ;Friedrichshafen G.IIIa: This sub-variant reintroduced a box-shaped biplane tail unit which improved the aircraft's control response when it was being flown on one engine. Another modification was the installation of a third 7.92 mm machine gun to combat British night fighters, which often attacked German bombers from below where they were hard to spot but the bomber's silhouette was easy to see against the night sky. This gun was mounted on a tubular, sliding mounting bolted to the floor of the rear gunner's position and was fired downward through a small sloping gun-tunnel cut into the bottom of the rear fuselage. By the last year of the war, the G.IIIa had replaced the G.III in production. ;Friedrichshafen G.IIIb: Towards the end of the war, the G.IIIa was further modified by re-designing the rear gunner's position, which was connected to the pilot's cockpit by an open passageway. ;Friedrichshafen G.IIIa Series 54: A license for the production of the Friedrichshafen G.IIIa was acquired by the Oesterreichische Flugzeugfabrik A.G. for the Austro-HungarianLuftfahrttruppe but the project was cut short before production began by the end of World War I. ;Transport and airliner conversions: After the end of World War I, the German government and at least one commercial airline, Deutsche Luft-Reederei, operated a fleet of Friedrichshafen G.III series aircraft which were used to transport mail, high priority cargoes and the occasional passenger to and from a variety of destinations including some long distance flights to Ukraine. For this purpose, a standard bomber, usually a G.IIIa or G.IIIb, was subjected to a set of modifications ranging from the simple disarmament to fitting a rudimentary cargo compartment in place of the rear gunner's position. Some of the DLR aircraft had the rear gunner's position replaced with a fully enclosed, glazed passenger cabin. Eventually, all these operations were stopped by the Allies in accordance with the Treaty of Versailles.
Operations
In front-line service with the Luftstreitkräfte, the G.III series equipped a large portion of the bomber force until the end of the war. The G.III series bombers served mainly on the Western Front where they were used to great effect. Being the most numerous German bomber type, Friedrichshafen G.III/IIIa bombers would have been responsible for much of the damage done by the German bomber force. Friedrichshafen bombers were used for attacks on tactical targets behind the Allied lines as well as for strategic air raids on major urban centers such as Paris. As far as is known no Friedrichshafen bombers of any type ever participated in strategic air raids on Britain. The attacks on Britain were conducted exclusively by Gotha G.IV and G.V medium bombers, Zeppelin Staaken R.IV heavy bombers and Zeppelin airships. The G.III was generally well liked by its military crews for its load carrying capability, reliability and robustness. These same qualities also made it popular with commercial operators during its short post-war career as a transport aircraft and airliner. Polish Air Force captured 2 German aircraft in 1919, when they performed courier flights to Ukraine over Poland. One of them was used in combat during Polish-Soviet War from September 1920 in the 21st Destroyer Escadre, among others bombing Zhmerynka station on 11 October 1920. The second aircraft remained in reserve. There was also the third bomber bought, but there is no information as for its usage.
Operators
Luftstreitkrafte
Lithuanian Air Force - 2 aircraft out of which reportedly one was flying in 1920-1923.