In 1920, the Air Ministry issued a requirement for a long-range bomber to replace the Vimy. Vickers initially responded to the specification attached to this DoR Type 4 requirement with its Type 57 development of the Vimy, with the span increased to 86 ft 6 in (26.21 m), a biplane tail unit and a powerplant of two Napier Lion W-type piston engines, each rated at 450 hp (335.5 kW). The name Vulcan was at first allocated to the type, but as work proceeded on the design the name was altered to Virginia, in accordance with the Royal Air Force’s recently adopted policy of naming bombers, transports and flying boats after places. The Air Ministry ordered an initial pair of prototypes that were at first designated as the Virginia I and Virginia II, but later accorded the retrospective designations Virginia Mk I and Virginia Mk II. The Virginia Mk I made its first flight on 24 November 1922, and immediately revealed inadequate directional control. The vertical tail surfaces and rudder-control system were modified, and then the rudders were increased in area, and this latter finally produced effective although very heavy directional control. In this form, the Virginia Mk I completed its initial trials and was then taken in hand, at express Air Ministry order, for revision with upper-wing `fighting tops’: located just outboard of the discs swept by the two propellers, these were long nacelles, installed with most of their depth below the wing and each carrying a fore-and-aft pair of gunner’s positions, each equipped with a Scarff ring mounting for one 0.303 in (7.7 mm) Lewis trainable machine gun, which complemented the standard pair of 0.303 in (7.7 mm) Lewis trainable machine guns installed singly in the nose and dorsal positions. The bomb load comprised nine 112 lb (51 kg) bombs carried in a lower-fuselage weapons bay.
Late in 1924, the Virginia Mk I was revised with a powerplant of two Rolls Royce Condor III Vee piston engines, each rated at 650 hp (485 kW), and at the same time the aileron-control circuit was modified and a third rudder was added on the centre-line. When the aeroplane made its first flight in this revised form during October 1924, it revealed great instability in the longitudinal plane and considerable heaviness in the lateral plane. The latter was cured by a modification of the gear ratio in the aileron control system, but the former proved insensitive to the addition of ballast weight in the nose and was cured only be the relocation of the engines some 2 ft 1 in (0.635 m) farther forward. In this form the aeroplane was much improved, and further enhancement of the type’s handling characteristics was affected by the addition of a fixed fin ahead of the central rudder. After the completion of flight trials in this form, the Virginia Mk I was further modified as the Virginia Mk VIII prototype, the changes including a 6 ft 0 in (1.83 m) lengthening of the rear fuselage, the addition of a new forward fuselage, the modification of the upper- and lower-wing outer panels with 2.5° of dihedral, and the alteration of the `fighting tops’ to much smaller units with their forward positions removed. After another round of trials, the aeroplane was again modified, in this instance to typical Virginia Mk VII standard, with outer wing panels swept at 6°. In this form the aeroplane was used by Nos 7 and 10 Squadrons for operational trials of the `fighting top’ concept. At the end of 1928, the Virginia Mk I received its final modification, in this instance to Virginia Mk X standard, for the use of No 7 Squadron. By this time, the aeroplane retained virtually nothing of its original features, and had an essentially metal airframe in place of its original wood.
The second aeroplane was completed to Type 76 standard with the RAF designation Virginia Mk II, and was somewhat different from the Virginia Mk I in details such as its Lion II engines in better streamlined nacelles, and cooled by semi-circular Lamblin radiators installed between the main landing gear unit Vee strut pairs, a longer nose incorporating an improved bombardier position, provision for the incidence of the tailplane to be altered in flight by the incorporation of a hinged joint in the rear fuselage, and the provision of greater legroom in the cockpit by altering the weapons bay for a maximum of eight rather than nine 112 lb (51 kg) bombs. The Virginia Mk II first flew in April 1924, and on the completion of its trials was allocated to No 7 Squadron for operational trials.
FIRST PRODUCTION VIRGINIA
The Type 79 model was the first production version of the Virginia family, but was produced to only six aircraft, the first two of them as prototypes to Specification 1/21, which was based on the Virginia Mk II with dual controls, provision for the underwing carriage of two bombs of up to 550 lb (249 kg) weight for a maximum bomb load of 1996 lb (905 kg), and provision for a 0.303 in (7.7 mm) Lewis trainable machine gun in a position under the fuselage. The Type 99 (Mk IV) variant was identical to the Type 79 (Mk III) in all except its extra electric gear, an increase in the number and positioning of bombs that could be carried and, as a retrofit, an additional centrally mounted rudder. Production totalled a mere three Virginia Mk IV aircraft. The Virginia Mk V was a development of the Virginia Mk IV, with the centrally mounted rudder and, for the first time in a British bomber of the period between the world wars, an overall finish of dark green in place of the standard silver of that time. Ordered to Specification 12/24, this was the first major production model of the Virginia bomber family, and production totalled 22 aircraft.
The Virginia Mk VI, known as the Type 108 in the company nomenclature, resulted from criticism of the Virginia Mk V’s outer-wing panel folding system for easier hangarage. A revised folding system was therefore introduced together with a revision of the outer panels so that they had 2.5° of dihedral on both the upper and lower panels rather than 4° on only the lower panels, as had hitherto been the case. Orders for the Virginia Mk VI totalled 25 new-build aircraft, and six Virginia Mk V bombers were revised to the same standard.
There was considerable service criticism of the Virginia which, it was justly claimed, lacked real use in the bomber role, as the pilot had to concentrate all his attention on the flying of the aeroplane, rather than on its best employment in operational terms. The problem here was the poor handling in the air of the Virginia, which was still longitudinally unstable under all conditions, directionally unstable as soon as the pilot had lost the horizon, and laterally unstable in turbulence. It was soon established that this problem resulted in part from the addition of extra equipment, including the tail gun position, which had moved the centre of gravity too far to the rear, and in part from deficiencies that had been evident even in the Virginia Mk I. The solution to this problem, it was felt, was a combination of a slight sweepback angle on the outer wing panels to move the centre of lift back into the right position relative to the centre of gravity, for improved longitudinal stability and controllability, and the adoption of Frise ailerons for better lateral control. The chosen sweepback angle was 2.5°, but then the Air Ministry intervened with a demand that the radio equipment should be moved to a position behind the rear spar bulkhead, which moved the centre of gravity so far to the rear that a sweepback angle of 7.5° would have been required. This would have raised considerable structural problems, so a compromise angle of 6° was chosen for the converted Virginia Mk III prototype, which became the Type 112 and as such the Virginia Mk VII prototype. In its fully revised form, this machine made its first flight in August 1925, and revealed handling characteristics transformed wholly for the better. The decision was thus taken to built 11 aircraft to the definitive Type 122 standard with Lion II engines replaced by Lion V engines, each rated at 570 hp (425 kW), as well as the other changes incorporated in the Type 112 prototype, and to convert another 38 existing aircraft to this standard.
Trials of a rear gun position in a converted Virginia Mk VII proved so successful that all thoughts of `fighting tops’ were immediately abandoned. Production of this revised Type 128, the Virginia Mk IX, totalled eight aircraft, and another 27 existing aircraft were adapted to this standard. As was the case with the Virginia Mk VII, aircraft of the Virginia Mk IX series were used widely for experimental work in addition to their standard squadron duties.
After the concept of metal wings had been validated by structural tests of a set of metal wings for the Vimy bomber, within the context of the Vickers Vigilant flying boat design of 1920, the Air Ministry asked Vickers to design fabric-covered metal wings for trials on the Virginia bomber. Vickers was already working on a metal rear fuselage for the Virginia Mk VII for a weight saving of 49 lb (22 kg), and the sensible decision was made to add metal wings to this prototype conversion for an overall weight saving of 1100 lb (499 kg). The revised aeroplane first flew in May 1927, and, after a number of teething problems, proved so successful that it was decided to proceed with the full metalisation of the airframe, including a revised tail unit with a pair of aerodynamically balanced rudders without fins. The Virginia Mk VII conversion proved so successful that its standard was accepted for all future Virginia orders. Production to this Type 139 standard totalled 50 Virginia Mk X aircraft, and 53 existing aircraft were rebuilt to the same standard.