C.Andrews Vickers Aircraft since 1908 (Putnam)

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   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.

P.Lewis The British Fighter since 1912 (Putnam)

In their endeavours to produce a successful two-seat tractor fighter, Vickers evolved several variants of their basic F.B.24 design. The machine was first discussed at the end of 1916 as a fighter reconnaissance biplane to be designed around the 150 h.p. Hart radial engine but finally appeared in 1917 with the 200 h.p. Hispano-Suiza installed and designated F.B.24B. Its appearance was that of a normal unequal-span two-bay biplane with rather angular and inharmonious lines.
   A new version, the F.B.24C, made its bow with the 285 h.p. Lorraine-Dietrich 8Bd engine and embodied a modified fin of smaller size, besides being tried out with a pair of side radiators as an alternative to the frontal type.
   The field of view from the pilot’s cockpit under the upper centre-section was considered to be far too restricted for a fighting aircraft and an attempt was made in the F.B.24E to rectify the fault by raising the fuselage to the level of the upper wings and filling the resulting gap below the fuselage to the lower planes with the Hispano-Suiza’s radiator. The pilot’s upward view was vastly improved but at the expense of his downward vision.
   The general layout of the F.B.24E was carried forward into the F.B.24G which was given larger wings of equal span and the 375 h.p. Lorraine-Dietrich 13 as its power unit with two side-mounted radiators. None of the F.B.24 variants was eventually accepted for service.

F.Mason The British Fighter since 1912 (Putnam)

Vickers F.B.24

   Harold Barnwell’s F.B.24 was, like some products of other commercial manufacturers, dogged by official refusal to make available Hispano-Suiza engines for production aircraft on the grounds that delayed production of the engine resulted in all those available being reserved for the S.E.5. When originally projected in the late autumn of 1916, the F.B.24 had been intended to have a 150hp Hart radial engine, but this had met with general disapproval in the F.B.16, and its use was evidently abandoned. Vickers did, however, manage to acquire a 200hp Hispano-Suiza engine for prototype use, and the first aircraft thus powered, the F.B.24B, is said to have been flown at the end of March 1917.
   The F.B.24B was a well-proportioned two-bay biplane, intended as a reconnaissance fighter, the wings being of unequal span; the top wing was built in two halves which joined on the aircraft’s centre-line, without centre section. The pilot, being situated directly below the upper wing (with two small clear panels in it), possessed a very poor field of view, while the observer, armed with a Lewis gun on Scarff ring, was located in line with the wing trailing edge which, although cut away, severely restricted the gun’s field of fire.
   The performance with the Hispano engine was modest, and it was generally felt that the F.B.24B was underpowered. The next variant to be built, the F.B.24C, was therefore powered by the 275hp Lorraine-Dietrich 8Bd, and both front and side radiator versions were flown; the long curved tail fin, fitted previously, was shortened. This version returned a top speed in the region of 133 mph at sea level.
   On account of the criticism of the crew’s poor location, the last two versions built, the F.B.24E and the 24G were re-designed with the top wings attached to the upper fuselage longerons, so that both pilot and observer/gunner had unrestricted view all round above the wings. On both aircraft the lower wing was located clear of the underside of the fuselage, the wing shape and interplane struts remaining much the same as on the F.B.24C, and also retaining the shortened tail fin. However, whereas the F.B.24E was powered by the 200hp Hispano-Suiza, the F.B.24G was fitted with a 375hp Lorraine-Dietrich 13 V-12 engine; the latter was an ungainly-looking aeroplane with lengthened, unstaggered wings and enlarged tailplane, bulky engine installation and ailerons apparently fitted only on the upper wing. Untidy radiators were attached to the sides of the fuselage. Maximum speed was said to be about 140 mph at sea level.
   Although not looked upon with much favour by British authorities, the F.B.24G is said to have been produced by Darracq in France after the War.


   Type: Single-engine, two-seat, two-bay biplane reconnaissance fighter.
   Manufacturer: Vickers Ltd (Aviation Department), Knightsbridge, London.
   Powerplant: F.B.24B and F.B.24E, 200hp Hispano-Suiza. F.B.24C, 275hp Lorraine-Dietrich 8Bd. F.B.24G, 375hp Lorraine-Dietrich 13.
   Dimensions: F.B.24C. Span, 37ft 6in; length, 26ft 6in; wing area, 384 sq ft. F.B.24G. Span, 38ft 3in; length, 30ft 0in; wing area, 450 sq ft.
   Weights: F.B.24C. Tare, 1,709lb; all-up, 2,650lb. F.B.24G. Tare, 2,332lb; all-up, 3,680lb.
   Performance: F.B.24C. Max speed, approx 133 mph at sea level; climb to 10,000ft, 11 min; service ceiling, 23,000ft; endurance, 3 hr.
   Armament: All versions up to and including F.B.24E armed with one synchronized 0.303in Vickers machine gun on nose, and one Scarff ring-mounted Lewis gun on rear cockpit. The F.B.24G may have been armed with twin synchronized Vickers guns.
   Prototypes: Number built not known (first flight by F.B.24B believed to have taken place in March 1917). No production in Britain.

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).

J.Bruce British Aeroplanes 1914-1918 (Putnam)

Vickers F.B.24

  THE original Vickers F.B.24 design was projected in December, 1916, as a two-seat fighter-reconnaissance biplane powered by the 150 h.p. Hart radial engine. By that time the Hart had been flown in the original F.B.16 and had apparently proved to be unsatisfactory, for the F.B.24 was never built with that engine.
  Attempts were made to obtain suitable alternative engines, but the authorities would not release any. At that time all available Hispano-Suizas were wanted for S.E.5s, all Rolls-Royce Falcons for Bristol Fighters, and all B.H.P.s for D.H.4s.
  Ultimately the F.B.24 was re-designed to have the 200 h.p. Hispano-Suiza and was flown with that engine. The completed aircraft was a well-proportioned two-bay biplane with wings of unequal span and chord. The upper wing, typical of Vickers practice, was made in two halves which met at the apex of a trestle-shaped cabane. The pilot sat directly under the upper wing and had no upwards view apart from what was provided by two very inadequate cut-outs above his head. The observer sat a short way farther aft. The type number F.B.24B was given to the aircraft.
  The fuselage was a simple structure, basically of rectangular cross-section and surmounted by a rounded top-decking. The engine had a flat frontal radiator, and the original tail-unit incorporated a long, low aspect-ratio fin with rounded leading edge similar to the surface fitted to the F.B.16 and F.B.19.
  Performance was good, but was improved upon by the F.B.24C, a new variant which was powered by the 275 h.p. Lorraine-Dietrich 8Bd engine. The F.B.24C had the same configuration as the original machine, but the fin was shortened and reduced in area. This sub-type appeared with both a frontal radiator and twin side radiators. The position of the pilot limited his view so severely that the F.B.24’s fighting efficiency would have been poor if it had been put to the test of combat. By drastic modification this was remedied: the F.B.24C was followed by the extensively re-designed F.B.24E variant in which the fuselage was raised to such a level that it was attached directly to the upper wing, and the pilot sat between the spars with his head completely above the wing. He therefore had an uninterrupted view of the entire upper hemisphere. The gap between the fuselage and the lower wing was occupied by a ventral radiator. The engine was a Hispano-Suiza. The smaller fin and rudder as used on the F.B.24C were retained, but the top-decking of the fuselage terminated a short way aft of the observer’s cockpit; behind that point the top surface of the fuselage was flat.
  Of generally similar layout was the Vickers F.B.24G, an enlarged, equal-span development which was powered by the big Lorraine-Dietrich 13 engine, a vee-twelve which delivered 375 h.p. In the F.B.24G, the generally handsome lines of the F.B.24 design were lost. The engine cowling was bulky, and the equal-span wings appeared to have a disproportionately narrow gap. The upper wing was attached directly to the upper longerons, and the pilot and observer were above it. There was a clear gap between the bottom of the fuselage and the lower centre-section; two side radiators were fitted. At one time at least ailerons were fitted to the upper wings only, but it seems that later they were also fitted to the lower wings.
  The F.B.24G was the last F.B.24 sub-type, and was too late to be developed for any Service use.


SPECIFICATION
  Manufacturers: Vickers Ltd. (Aviation Department), Imperial Court, Basil Street, Knightsbridge, London, S.W.
  Power: 200 h.p. Hispano-Suiza. F.B.24C: 275 h.p. Lorraine-Dietrich 8Bd. F.B.24G: 375 h.p. Lorraine-Dietrich 13.

Weights (lb) and Performance:
Engine 200 h.p. Hispano-Suiza 2.75 h.p. Lorraine-Dietrich 375 h.p. Lorraine-Dietrich
Weight empty 1,630 1,709 2,332
Military load 185 185 406
Crew 360 360 360
Fuel and oil 435 396 582
Loaded 2,610 2,650 3,680
Maximum speed (m.p.h.) at
5,000 ft 122 - -
10,000 ft 118 129-5 -
15,000 ft - 123 -
m. s. m. s. m. s.
Climb to
5,000 ft 6 45 - - - -
10,000 ft 15 00 11 00 - -
15,000 ft - - 18 00 - -
Absolute ceiling (feet) 16,000 23,000 -
Endurance (hours) 3 3 3

Dimensions:
Engine 200 h.p. Hispano-Suiza * 275 h.p. Lorraine-Dietrich 375 h.p. Lorraine-Dietrich
ft in. ft in. ft in.
Span:
  upper 35 6 37 6 38 3
  lower 30 0 31 0 38 3
Length 26 0 26 6 30 0
Chord:
  upper 6 6 6 9 6 6
  lower 5 0 5 0 6 6
Gap 4 6 4 6 4 7
Stagger 0 11 2 0 nil
Dihedral 2° 2° 1° 30'
Incidence 2° 2° 2°

Areas:
Engine 200 h.p. Hispano-Suiza * 275 h.p. Lorraine-Dietrich 3.75 h.p. Lorraine-Dietrich
sq ft sq ft sq ft
Wings:
  upper 207 247 219
  lower 133 137 231
  total 340 384 450
Ailerons:
  total 36 33 48
Tailplane 21 29 34
Elevators 22 25 29-6
Fin 9-25 9-25 8
Rudder 8-25 8-25 9
* These particulars probably relate to the F.B.24E.

  Armament: Both Hispano-Suiza versions and the F.B.24C had one fixed, forward-firing Vickers machine-gun for the pilot, synchronised to fire through the airscrew, and one Lewis machine-gun on a Scarff ring-mounting on the rear cockpit. The F.B.24G probably had twin fixed Vickers guns for the pilot. There was a Lewis gun on a Scarff mounting on the rear cockpit.

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.

Журнал Flight

Flight, June 12, 1919.

"MILESTONES"

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.