The S.B.5 was a test bed to examine flight characteristics using highly swept wings. The single example S.B.5 (WG768) first flew in December 1952 on the 3500lb (1588-kg) thrust of its Derwent turbojet, and piloted by Roland Beaumont. Though modelled aerodynamically on the Mach 2 English Electric P.l., was intended to investigate the low-speed handling qualities of swept wings. The aeroplane was fitted with wings whose sweep could be adjusted on the ground at angles of 50 degrees for use with a T-tail, 60 degrees for use with a conventional tail or a T-tail, and 69 degrees for use with a T-tail.
The variable-incidence tailplane was later set at the bottom of the fuselage, as on the P.1.
On the S.B.5 wing there is an unusual fixed "droop snoot" on a small portion of the centre section leading edge.
1958 tests included a 69 degree sweepback and a Bristol Orpheus engine.