A large single-engined biplane, it carried one gunner in a nacelle mounted on the upper wing to give an allround field of fire.

In early 1916, the British War Office drew up a specification for a multi-seat escort fighter to be powered by one of the new Rolls-Royce Eagle engines, intended to protect formations of bombers from German fighters such as the Fokker E.I, with an additional role of destroying enemy airships.

[1] While the specification did not require high speed, a good field of fire for its guns was essential,[2] while the secondary anti-Zeppelin role demanded an endurance of at least seven hours.

[1] The Vickers response, the F.B.11, designed by R. L. Howard-Flanders, was a large, single-bay, biplane of tractor layout.

The pilot and one gunner sat in separate but closely spaced cockpits under the trailing edge of the upper wing, while a second gunner sat in a nacelle, or "fighting top", attached to, and extending forward of the upper wing.