The French aviation concern of Caudron continued to evolve their serviceable G-series reconnaissance-minded biplanes during World War 1 (1914-1918). The G.3 of 1913-1914 emerged from the original prewar G.2 and from this also came the G.4 of 1915 (detailed elsewhere on this site). The G.6 model followed and this retained the G.4's recognizable twin-engine layout and sesquiplane biplane wing arrangement (the upper wing being of great span than the lower to reduce drag between the units) as well as the two-seat cockpit nacelle at center but added a more conventional tail unit and more defined fuselage shape. Gone were the skeletal, uncovered tailbooms of the original offering and, in their place, was a tubular fuselage with integral empennage mounting a sole vertical tail fin and applicable horizontal surfaces. The main wings remained with their dual bay arrangement, each assembly also holding its own engine nacelle with engines driving two-bladed propeller units. The nose section was faired over in a nicer streamlined fashion for aerodynamic efficiency. The undercarriage carried the twin-legged, four-wheeled tradition of earlier Caudron aircraft.
The G.6's design was attributed to one Paul Deville and a first flight was achieved during 1916. Service entry was in 1917 and the aircraft managed a tenure into the final months of the war as a reconnaissance platform. Additional service saw the line used in the artillery-spotting role to help improve general accuracy of ground-based artillery crews. G.6s were also pressed into the fighter escort role alongside heavier, slower bomber types and found success there as well. Approximately 512 Caudron G.6 aircraft were built with these serving solely with the French Air Service (the "Armee de l'Air') across an impressive 40 squadrons. During a 1916 three-month span alone, G.6 crews of Escadrille Caudron No. 46 claimed as many as thirty-four German aircraft - a notable feat for this much-forgotten aircraft line.
The G.6 featured its crew of two - a pilot and an observer - seated in tandem across open-air cockpits. The aircraft carried 2 x Le Rhone 9Jb engines of 130 horsepower output each allowing for a maximum speed of 96 miles per hour, a service ceiling of 15,500 feet, and a rate-of-climb near 865 feet per minute. Mission endurance was up to 2.5 hours which gave the aircraft good "legs" in the European Theater.
By this time in the war, Caudron aircraft were being outfitted with modest weaponry for both offensive sorties and defensive measures. 1 or 2 x 0.303 Lewis machine guns were set upon a trainable mount in the rear cockpit for the observer to manage. The guns provided a reach around the aircraft's critical "six" quadrant, the area behind the aircraft most vulnerable to attack by intercepting aircraft. The G.6 series was also cleared to carry up to 200lb of external drop ordnance - suitable for engaging ground targets of opportunity as the crew found them. Of course, such bombing runs were typically held at low-level and opened the crew and aircraft alike to dangerous ground-based fire.
Caudron continued their work in the biplane aircraft field throughout the war. In 1918, the French introduced the Caudron R.11 which utilized a similar rounded, streamlined fuselage, single tail fin, and biplane wings to serve as a reconnaissance platform, light bomber, and escort fighter.
Caudron produced over 4,000 aircraft for World War 1 service. It was later absorbed under the Renault banner in 1933.