Harrier with a Twist: the Hawker-Siddeley HS.1175

Among the many unbuilt Harrier evolutions investigated over the years was the HS.1175 of the late 1960s; this was definitely an outgrowth of the basic Harrier (which was just really taking shape itself at that point) but had a stretched airframe fitted with a two-poster Pegasus configuration and a Rolls-Royce/Allison XJ99 lift engine of around 9,000lbs thrust. This would have had an extra pair of pylons, but of course would have also incurred the disadvantage of having haul around the lift engine (albeit fairly lightweight for the time) that would only be used on take off and landing. The 1175 never went forward, although the XJ99 was proposed for use in other V/STOL designs such as the Convair Model 200.

Hawker-Siddeley HS.1175 V/STOL fighter color profile

 

A USAF Harrier? Not Quite