The Vickers Type 161 was an unusual 1930s pusher biplane interceptor, designed to attack aircraft from below with a single upward-angle large calibre gun. The aircraft flew well but the concept was abandoned and only one was built.
The Vickers 161 was designed in response to Air Ministry specification F.29/27. This called for an interceptor fighter operating as a stable gun platform for the COW 37 mm gun produced by the Coventry Ordnance Works (COW) that fired 23 oz (0.65 kg) shells. The gun was to be mounted at 45 degrees or more above the horizontal, so that the aircraft could fly below the target bomber or airship, and fire upwards into it.