A French twin engine biplane, widely used during World War I as a bomber aircraft. It was the first twin engined aircraft in service in any numbers with the French.
Designed by René and Gaston Caudron as an improvement over their single engined Caudron G.3. The aircraft employed wing warping for banking. First built in 1915 the G.4 was also manufactured in France, England and Italy.The G.4 was in use in Belgium, France, Finland, Italy, the United Kingdom, and the United States.
The G.4 entered service with the French Aéronautique Militaire in November 1915. The Caudron G.4 was used to carry out bombing raids deep behind the front line, being used to attack targets as far away as the Rhineland. When Germany developed a fighter force increasing losses led to its withdrawal from day bombing missions. The French, in the autumn of 1916, used the aircraft solely for night bombings.
The British Royal Naval Air Service (RNAS) also used the G.4 as a bomber, receiving 55, of which twelve were licence built by the British Caudron company and the remainder supplied from France. Number 4 and 5 Wing RNAS using the G.4 for attacks against German seaplane and airship bases in Belgium. It was finally replaced in RNAS service by Handley Page O/100 aircraft in the autumn of 1917.
Italian G.4s proved successful in operating in the mountainous Alpine fronts, where its good altitude capabilities proved useful.
The G.4 was also used by the Imperial Russian Air Force for reconnaissance purposes.