C.Andrews Vickers Aircraft since 1908 (Putnam)
The F.B.24 was a straightforward two-seat tractor biplane for fighter reconnaissance and comparative with the Bristol Fighter, designed by Capt Frank Barnwell, brother of Vickers' Harold Barnwell. It was yet another design intended for the ill-fated Hart engine and followed the familiar pattern in being fitted with a variety of makeshift power units. The prototype, designated F.B.24A, had the 200 hp Hispano Suiza, as did also the second airframe, the F.B.24B; the F.B.24C was fitted with the 275 hp Lorraine-Dietrich in the French works of S. A. Darracq while the F.B.24D had the 200 hp Hispano Suiza. In the F.B.24E the upper wing was attached directly to the top of the fuselage, to improve the view of the crew. The F.B.24G with the large 375 hp Lorraine was built by Darracq in France and did not fly until some time after the war; it used the wing and fuselage arrangement of the F.B.24E, but was an ungainly aeroplane.
F.B.24E - One 200hp Hispano Suiza. Span 35 ft 6 in, upper, and 30 ft, lower; length 26 ft; wing area 340 sq ft. Empty weight 1,630 lb; gross weight 2,610 lb. Max speed 122 mph at 5,000 ft; climb to 10,000 ft - 15 min; absolute ceiling 16,000 ft; endurance 3 hr. Armament one Vickers gun and one movable Lewis gun.
H.King Armament of British Aircraft (Putnam)
F.B.24. This two-seater was built late in 1916 and was a counterpart of the Bristol Fighter. In all armed variants there was a Scarff ring-mounting for a Lewis gun, emplaced close behind the pilot under a large trailing-edge cut-out. Variants before the F.B.24D had, or were intended to have, a single fixed Vickers gun for the pilot, but the D variant had two Vickers guns, wholly cowled in and firing above the engine. This variant was perhaps the most formidably armed fighter of its time. Even greater interest attaches to the F.B.24E, which was a major redesign having the top wing attached directly to the upper longerons and flown from the rear seat. The occupant of the front seat sat high in the fuselage with his head protruding through a circular hole.
There has been speculation concerning the purpose of this aeroplane, but the present writer inclines to the belief that it was intended to carry a Vickers automatic 1-pounder gun on a Vickers mounting. There is clear evidence that during 1917 Vickers were working on the mounting illustrated in drawings herewith. This may have been a development of that installed on the F.B.7 and was certainly designed for an aeroplane and not an airship. Light weight and 'large angles of training and depression' were sought in this design. The mounting comprised a fixed ring which supported a carriage comprising two longitudinal plate girders, cross-braced, and provided with clips which, by contact with the ring, prevented the carriage from lifting when the gun was fired. The carriage was capable of all-round traverse, the training gear comprising a pinion, mounted on the carriage and driven through worm gearing through a hand wheel, meshing with rack teeth on the ring. At their forward ends the plate girders had upward extensions to receive the gun trunnions, and between one of these extensions and the gun was a worm-wheel segment gearing with a worm mounted on the carriage and driven by the elevating handwheel. The rear part of one of the girders carried a seat for the gunner, who therefore moved with the gun. It was suggested by Vickers that the ring, instead of being installed horizontally, could be disposed 'at an angle to the horizontal so that the weight of the parts moving in training can be utilised to assist in the training of the gun against the wind pressure'. The sight comprised a sight-bar pivoted to the gun carriage and moved by the elevating gear through an angle equal to that given to the gun.
The French-built F.B.24G had the lop wing mounted as on the F.B.24E, but the gunner was in the rear cockpit, which had a Scarff ring-mounting for a Lewis gun. The pilot had two 'buried' Vickers guns.
W.Green, G.Swanborough The Complete Book of Fighters
VICKERS F.B.24 UK
A two-seat fighter-reconnaissance aircraft, the F.B.24 was yet another Vickers aircraft originally designed for the ill-fated and Vickers-sponsored Hart radial engine. The prototype was completed in December 1916, but unavailability of the Hart engine resulted in its modification to accept the 150 hp Hispano-Suiza water-cooled engine as the F.B.24A, and the second airframe, the F.B.24B, being similarly powered. An unequal-span two-bay biplane, the F.B.24 had an armament of one fixed synchronised Vickers gun and one Lewis on a Scarff ring mounting. Both F.B.24A and 24B were re- engined with the 200 hp Hispano-Suiza with which they were redesignated as F.B.24Ds. Similar in general configuration was the F.B.24C, which was powered by a 275 hp Lorraine-Dietrich 8Bd water-cooled eight-cylinder Vee-type engine and armed with two synchronised Vickers guns, provision being made for emergency dual control in the gunner’s cockpit. The F.B.24C and D both possessed good performance, but the limited view offered from the pilot’s cockpit was considered unacceptable. Consequently, the Vickers team revised the basic design by lowering the upper wing so that it was attached directly to the upper longerons, the front cockpit being situated between the wing spars. With this change, the aircraft was designated F.B.24E and power was provided by a 200 hp Hispano-Suiza. This same configuration was adopted for yet a further version of the design, the F.B.24G, which was a larger aircraft than its predecessors, with two-bay wings of equal span and chord and a 375 hp Lorraine-Dietrich 12-cylinder Vee-type engine. The F.B.24G was built in France by the Darracq concern, but it did not fly until 26 May 1919, and its performance and fate have gone unrecorded. The following data relate to the F.B.24D.
Max speed, 118 mph (190 km/h) at 10,000 ft (3 050 m).
Time to 10,000 ft (3 050 m), 15 min.
Endurance, 3.0 hrs.
Empty weight, 1,630 lb (739 kg).
Loaded weight, 2,610 lb (1184 kg).
Span, 35 ft 6 in (10,82 m).
Length, 26 ft 0 in (7,92 m).
Wing area, 340 sqft (31,59 m2).
Flight, June 12, 1919.
THE VICKERS MACHINES
The F.B. 24. (1916)
The next type of interest is the F.B. 24. This machine was originally designed in December, 1916, to take the Hart motor. The top plane was placed low, and the gunner, who was in the rear, had an excellent all-round field of fire.
After many vicissitudes, owing to the difficulty of obtaining from the Government engines of sufficient power, the type was abandoned for the time being. Later, the machine was re-designed to take various other engines, the 220 h.p. and 275 h.p. Lorraine being installed, also the 200 h.p. Hispano-Suiza. The results of the tests on this machine with the new 275 h.p. Lorraine engine proved to be very satisfactory, it attaining a speed of 130 m.p.h. at 10,000 ft., and climbing to this height in 11 minutes.