Vickers 150 / 195 / 225 Vanox
Initially a private venture, the submission of Vickers design to the Air Ministry coincided with the issuing of Air Ministry specification B.19/27 for a Virginia replacement. Conceived as a biplane powered by the Bristol Jupiter radial engine it was to have much better performance than the Virginia with similar engines.
The B.19/27 specification meant that the Vickers submission would be tested competitively in trials against other manufacturer's designs. In the redesign to meet the specification, the B.19/27 project took the Virginia Mark X all moving rudder together with an all-moving tailplane. Three designs were submitted in total; two biplanes with Jupiter and geared Bristol Mercury engines respectively and a monoplane version. The Mercury engined design, the Vickers Type 150 was selected by the Ministry for consideration and building, now to be funded by the Ministry, started. Part way through it was agreed that an alternative engine was allowable, the Rolls-Royce F.XIV.
The aircraft was a two-bay biplane of all metal construction, with a biplane tailplane and with the two engines mounted between the wings.
The aircraft flew for the first time on 30 November 1929. Initial testing and evaluation showed that the aircraft had poor handling, being unstable laterally, prone to Dutch roll and to severe flexing of the rear fuselage. It was handed to the RAF in 1932. Following a forced landing it was rebuilt incorporating recommendations made in reports from Ministry test pilots to try to resolve these problems, and was powered by Kestrel III engines. It was then given the name Vickers Vanox by Vickers.
These changes did not solve the aircraft's handling problems, and the sweepback of the wings was reduced, which resolved the handling problems. The Kestrel engines proved unreliable, and were replaced by more powerful Bristol Pegasus radial engines. In this form, the aircraft was designated the Vickers Type 195 Vanox, and was demonstrated to meet the requirements of specification.
Following further modifications in February 1933 to improve performance, with extended, three bay wings being fitted, it was now designated the Type 255. However, by this time, the competing Handley Page Heyford and Fairey Hendon bombers had already been ordered into production.
The sole Type 255 spent most of its time in Malta (RAF Luqa) and Gozo on bombing trials and W/Ops training. The aircraft did not perform well and was removed from service after 1 year having been superceded by the Handley Page Heyford.
The Vanox did fly again very fleetingly in 1938 taking part in Air Refuelling trials by the Royal Aircraft Establishment in the Mediterranean, being flown for the last time on 7 January 1938.
Engines: 2 × Rolls Royce F.XIV, 480 hp (358 kW) each
Length: 60 ft 6 in (18.45 m)
Wingspan: 76 ft 6 in (23.32 m)
Height: 19 ft 3 in (5.87 m)
Wing area: 1,367 ft² (127 m²)
Airfoil: RAF 34
Empty weight: 10,435 lb (4,743 kg)
Loaded weight: 15,400 lb (7,000 kg)
Max. takeoff weight: 16,170 lb (7,350 kg)
Maximum speed: 125 mph (109 kn, 201 km/h)
Range: 920 mi (800 nmi, 1,481 km)
Service ceiling: 23,000 ft (7,000 m)
Wing loading: 11.3 lb/ft² (55.1 kg/m²)
Power/mass: 0.062 hp/lb (0.10 kW/kg)
Climb to 6,500 ft (1,980 m): 19 min 45 sec
Guns: 2 × .303 in (7.7 mm) Lewis Guns
Bombs: Up to 2,200 lb (1,000 kg) of bombs