Usually known as the COW-Gun Fighter, this prototype monoplane was one of two ordered by the Air Ministry (with the unorthodox Vickers Type 161) in fulfilment of Specification F.29/27. This called for an aircraft armed with the 37mm Coventry Ordnance Works (COW) cannon that had been evolved during World War I and was thought to have potential as an anti-bomber weapon. The COW gun was to be mounted at an upward angle of at least 45° from the horizontal, with the idea that the fighter would approach enemy bombers from below and astern. The Westland prototype was, in effect, an enlargement of the F.20/27 prototype, and had the COW gun mounted to fire upwards at 55°, with the breech casing in the starboard side of the open cockpit. Aiming was by means of a periscopic sight, and a special "ammunition dispenser" carried 39 rounds. The fighter was of similar all-metal construction to the F.20/27 and, like the latter, was first flown with a small fin and rudder which later had to be considerably enlarged to obtain satisfactory spinning characteristics. Powered by a 485hp Bristol Mercury IIIA nine-cylinder air-cooled radial, the F.29/27 first flew in December 1930, but the RAF quickly lost interest in the COW gun. With a Mercury IVA, the COW-Gun Fighter remained at the A & AEE until July 1934.

3-View

A three-view drawing (812 x 1071)