The Vickers Destroyer (either the second or third development pictured) was a type ahead of its time with the first rendition flying in 1912, it was intended to be a dedicated combat aircraft and was the first of such a type in Britain. It was cancelled though due to the progress of technology and aerodynamics. A slightly more streamlined version, the Vickers Gunbus saw widespread service in the early years of WWI (though it did not enter service until after the war's onset), though, personally, I think the Destroyer has a much better sounding name and it would have been nice to have seen the type enter service as this could have potentially shortened the duration of WWI.