Lotris Bdchereau, chief designer, had been responsible for the exotic A2 and A4, which had a gunner placed in a nacelle hinged to the forward fuselage - ahead of the tractor propeller. This was mainly due to the reluctance of British and French authorities to back the development of an interrupter mechanism, enabling a machine-gun to be fired through the propeller arc. Needless to say, this arrangement was extremely unpopular with its crews. Still, some 90 examples of the A2 were built, 42 for the Aviation Militaire (French Army Air Force) and 57 for the Imperial Russian Air Service. While the A2's career with the French was cut short, the Russians were forced to retain it in service due to shortage of aircraft, and even acquired a further 10 A4s, a development of the A2.