A production Whirlwind after modification to carry underwing bombs.

Whirlwind P7062 of 263 Squadron hit trees during a practice attack at Wroughton in May 1943.

The prototype L6844 after modification to production standard, with no mudguards, enlarged rudder and external exhausts, but with an experimental arrangement of the four cannon line-abreast in the nose.

The prototype L6844 with a 37-mm cannon in the nose.

A close-up of the Fowler flaps, showing how they were continuous across the fuselage and had attached to them the rear fairings of the nacelles.

The first prototype. Note also in this picture the exhaust stubs on the wing trailing edge, radiator outlet, mudguards (later discarded) and original rudder.

The second Whirlwind prototype, with enlarged rudder and small fin tailplane fairing - this was enlarged for production aircraft

The last Whirlwind to remain airworthy - and that only until May 1947 - was registered G-AGOI for use as a company "hack ” by Westland, having previously been P7048.

A model of the Westland F.37/25 fighter as it was in the Autumn of 1937. All the characteristic features of the Whirlwind design are obvious apart from the single tail unit.