The Sopwith 3F.2 Hippo was a prototype British two-seat fighter aircraft of the First World War.
It was not successful, the Bristol F.2 Fighter (already in production) being preferred by the Royal Flying Corps.
[1] While the British Air Board did not place an order for the Hippo, it did grant Sopwith a licence to allow it to build prototypes as a private venture.
The Hippo was designed to give the best possible view to the pilot and gunner, which dictated the aircraft's shape.
[5] When tested, it was found to have sluggish controls and poorer performance than the Bristol F.2 Fighter which was already in service.