Vickers F . B . 25 The Vickers F . B . 25 was a British two - seat night fighter prototype of World War I designed to attack enemy airship s . Completed in 1917 , it failed in its official flight tests that year and no order for production resulted . Design . In 1916 , Vickers Limited designed a two - seat pusher configuration biplane fighter , the F . B . 23 , to replace its obsolete Vickers F . B . 5 and F . B . 9 " Gunbuses " . A number of versions of the FB . 23 were planned depending on the engine used , with possible powerplants including a 150 hp ( 119 kW ) Salmson water - cooled radial engine , a 150 hp Hart air - cooled radial engine and a 200 hp ( 149 kW ) Hispano - Suiza 8 V - 8 engine . The pusher configuration was obsolete however , compared to prospective tractor aircraft such as the Bristol F . 2 Fighter , which was both faster than the estimated performance of the F . B . 23 and carried a heavier armament , so Vickers abandoned the F . B . 23 without an example being built . Vickers reworked the F . B . 23 to form the basis of a two - seat night - fighter , the F . B . 25 , to compete with the Royal Aircraft Factory N . E . 1 to meet a British requirement for a night fighter capable of attacking German airship s . The F . B . 25 used an identical tail and tail boom assembly to the F . B . 23 , but had modified wings and a completely new fuselage nacelle . The F . B . 25 was a two - bay biplane with unstaggered wings of equal span . Its nacelle was mounted between the wings , was unusually wide for an aircraft of its type in its day , and accommodated the two - man crew , a pilot and a gunner , in staggered side - by - side seats , with the gunners seat ahead and to starboard of the pilots . The gunner was armed with a single 1 . 59 - inch Breech - Loading Vickers Q . F . Gun , Mk II , popularly known as the " Vickers - Crayford rocket gun , " which despite its popular name was a lightweight 40 mm single - shot gun that fired shells and had no rocket - launching capability . Its tailbooms converged in elevation to meet at the rear spar of the tailplane . It had a single propeller , mounted in a pusher configuration . The aircraft had an oleo - pneumatic undercarriage , an unusual feature for the time . Plans called for the F . B . 25 to mount a small searchlight in the nacelles nose , have a nosewheel to reduce the chance of the aircraft turning over during night landings , and use the same 200 - horsepower ( 149 - kilowatt ) Hispano - Suiza 8 planned for the F . B . 23 . As design and construction progressed , Vickers made changes ; the searchlight and nosewheel were deleted , and as the 200 - horsepower engine was unavailable , Vickers substituted a 150 - horsepower ( 112 - kilowatt ) Hispano - Suiza . Operational history . Vickers completed the F . B . 25 prototype in the early spring of 1917 . Company flight testing revealed poor characteristics . The prototype was sent to Martlesham Heath in June – July 1917 for official testing , and official reports declared that the F . B . 25 had poor control characteristics , being " very dangerous " with the engine off , and " almost unmanageable in a wind over 20 miles per hour " . The aircraft was condemned as being completely unsuited for use as a night fighter . No further aircraft were built , and the lone F . B . 25 later crashed at Martlesham Heath .