Flight, July 1928

THE FAIREY III F
Napier "Lion" or Bristol "Jupiter"

   ADAPTABLE to a great variety of requirements, the III F, designed and built by the Fairey Aviation Co., Ltd., is produced in two main types - as a two-seater general-purpose machine and as a three-seater Naval reconnaissance type for service with the Fleet Air Arm. The two types are almost identical in all respects save that of crew accommodation, and perform the same general functions, i.e., day bombing, offensive and defensive fighting, photography, reconnaissance, gunnery spotting, &c. The three-seater carries, in addition to pilot and gunner or observer, a wireless operator who is seated between the two other occupants, in a position where he is in the closest communication with either.
   By way of further extending the utility of these two types the undercarriage of the III F can be either a wheel or a float type, the fuselage structure, &c, being designed to resist the loads peculiar to the twin-float type of undercarriage. Both types are now also available in two forms of construction: mixed wood and metal, or all-metal. The following notes deal with the all-metal version, and more particularly with the general purpose two-seater type, which is the one illustrated in the photograph.
   As the III F is equipped for general-purpose work, there is not the space here to refer to more than a small proportion of the equipment. The pilot's cockpit has all the usual number of instruments, &c, and a synchronised gun on the port side. The seat can be raised and lowered, and is deep enough to accommodate the seat type parachute if desired. Dividing the rear cockpit from the front is a metal bulkhead, in the lower portion of which, on the port side, are mounted airspeed indicator, altimeter and watch, so that they can be read easily by the gunner when he is lying prone for bombing, &c. The bomb sight is arranged to be mounted on the side of the trap-door opening. Below the trap door is a sliding panel in the fairing, so that no break in the fuselage lines is caused when the trap door is not in use.
   In the two-seater a camera of the automatic hand-operated type is fitted, in addition to the radio equipment. If the latter is of the modified type, as supplied to the British Air Ministry, it is possible to use the camera without withdrawing the radio installation. Tapping keys are provided in both cockpits. The wireless generator is mounted on a swinging arm, so that it can be swung inboard when not in use.
   The rear-gun mounting may be either of the Scarff-ring pattern or the new Fairey type, which has been specially designed to meet the requirements of a fast machine. Various bomb loads can be taken as standard equipment. For example, a total of 2 bombs of 230 lbs. (104-5 kg.) each or two of 250 lbs. (113-5 kg.) each, and four sighter bombs can be carried, or four bombs of 112 lbs. (51 kg.) each and four sighter bombs. Or two racks of 4 by 20 lb. bombs alone can be used. All bombs are carried under the main plane.
   Fuselage. - Of all-metal construction, with a stiff tubular central cellule forming the structure to which are attached the welded-tube engine mounting in front and the rear portion of the fuselage at the back. Covering is of fabric at the back, and aluminium panels in front.
   Wings. - Spars of drawn corrugated steel tube, of the section known as "double eight," with pressed ribs clipped to it. Covering of fabric.
   Engine installation. - The standard III F machine is equipped with Napier "Lion," but if an air-cooled power plant is desired, the machine can be fitted with the "Jupiter VIII" geared engine. The petrol system is arranged so that the pump delivers through the hand pump, so that in case of failure no time is lost in changing over.
   Undercarriage. - The land type has a Vee undercarriage with oleo shock-absorbing legs, while the seaplane type has a twin-float undercarriage with Duralumin floats.

Flight, June 1929

BRITISH AIRCRAFT AT OLYMPIA

THE FAIREY AVIATION CO., LTD.

   ONE of the most imposing individual exhibits at Olympia will be found on the Fairey stand, where no less than eight complete aircraft will be exhibited, in addition to smaller items such as airscrews, etc. These eight machines will be :-
   One Fairey III F, Napier "Lion XI," to be shown in skeleton.
   One III F 3-seater ("Lion XI") Fleet Air Arm Seaplane.
   One III F 2-seater (" Jaguar VI") General Purpose landplane.
   One "Fox" 2-seater (Rolls-Royce F) high-performance light day bomber.
   One Long-Distance Monoplane (Napier "Lion").
   One "Firefly II" (Rolls-Royce F) single-seater interception fighter.
   One single-seater fighter Ship 'plane with alternative land undercarriage (Rolls-Royce F).
   One Fairey two-seater Fleet fighter reconnaissance seaplane (Rolls-Royce F).

   The Fairey III F to be shown in skeleton will afford a very excellent opportunity for visitors to Olympia to inspect in detail the Fairey forms of all-metal construction. This was in fact, the machine from which we obtained most of the sketches which illustrate this article, and as the III F is largely typical of other Fairey machines shown, with certain detail variations, it will also be used here as a basis for a brief description of Fairey metal construction in general, bearing in mind the fact that the construction to be described is only broadly similar in some of the other types and not absolutely identical.
   Mr. C. R. Fairey was one of the first British constructors to adopt welded steel tube fuselage construction, and as a result of very extensive experiments on a very large number of joints, he became convinced of the mechanical soundness of welding if properly carried out. Gradually a system has been evolved at Hayes which has been found not only rapid and cheap in production, but also to stand up well to its work under actual service conditions. It should be realised that at the present time there is probably something like 200 Fairey III F machines in service in various parts of the world, and if the special Fairey form of welded construction had been at all likely to develop any fault, it stands to reason that this would have been discovered long ago. Consequently one may justifiably assume the Fairey form of welded steel tube fuselage construction to be thoroughly reliable.
   In this connection it should be pointed out that Fairey does not, like Fokker for example, employ welded construction throughout. For instance, the front portion of the fuselage has longerons and struts with end fittings in the form of plugs pinned into the tubes, the plugs being formed with either plain eye bolt ends or with fork ends. These end fittings in turn are bolted to steel "spools," which also carry the anchorages for any bracing wires, etc. It may be recalled that even in the days before all-metal construction the Fairey Aviation Co. made use of these "spools" at certain points such as where lower wings, top centre-section struts and undercarriage struts were attached. The "spools" have been retained after the rest of the structure became all-metal.
   Forward of the backbone or central cellule formed by the bolted tubes is attached the engine bearer, itself a welded steel tube structure. The joints between the engine bearer and fuselage proper are made on "spools." Aft of the central cellule, also joined by "spools," the fuselage structure makes use of the Fairey form of welded construction. The longerons in this portion run through from rear spool to sternpost. The struts in the sides and those in top and bottom bays, instead of being individually attached, as is more usually done, are made up into the form of a panel or frame, the strut ends being welded to plates which, when in place on the machine, rather more than half surround the longerons, to which the plates are riveted, thereby locating the panel on the longerons. It will be seen that with the Fairey form of welded construction, the longerons themselves are not affected at all by the welding process, and this may have something to do with the good results obtained.
   The Fairey all-metal wing construction differs slightly according to the type of machine, but in the case of the III F's of all types, and some of the other types, the main wing spars are steel tubes which were originally of circular section and fairly large diameter, but have been formed into a section known as the "double eight." Up to a certain size of machine this form of spar has been found to be very good, and it is certainly simple to use, the attachment of fittings being a very easy matter. The wing ribs are of duralumin and consist of pressed webs which have lightening holes in them, and also vertical flutings formed on them for stiffness. Finally it should be pointed out that all steel parts are protected against corrosion by cadmium plating, and all duralumin parts anodically treated.
   These brief notes must suffice as an indication of the broad general principles of Fairey all-metal construction, and the individual aircraft to be exhibited at Olympia can now be dealt with in what detail may be permissible in the case of each machine. Air Ministry restrictions will prevent a very full discussion of the features of several of the types, as they are still released for "Part Publication" only.
   As the III F is the type by which the name Fairey has become known throughout the world, this will be dealt with first. It is probably a well-known fact that the Fairey III F is one of the most "versatile" types of aircraft ever produced in this or any other country. Apart from the fact that this type of machine can be supplied either as a two-seater, General Purpose landplane, as a Fleet Air Arm three-seater, as a Naval Reconnaissance machine, and as a landplane or seaplane in these various classes, the range is further extended by the fact that a great variety of engines, British and foreign, can be fitted according to the requirements of customers, water-cooled and air-cooled engines being installed as desired.
   The Fleet Air Arm three-seater III F to be exhibited at Olympia will be fitted with a Napier "Lion XI" engine, and will be shown as a seaplane, with standard float undercarriage which consists of tubular steel struts carrying two Duralumin floats. The rear legs of the float chassis are telescopic and incorporate shock absorbing equipment. The floats themselves are large (each of about 190 cub. ft. volume), and carry water rudders on their sterns, operated by the rudder pedals of the air rudder controls. Provision is made in the design of the floats for attachment of beaching wheels, which can be quickly attached and again detached.
   As already mentioned, the III F is produced both as a two-seater and as a three-seater. The seaplane exhibited has the three-seater arrangement, which differs from that of the two-seater mainly in the formation and dimensions of the deck fairings in the immediate vicinity of the rear cockpit.
   The Fairey III F is characterised by a long slender fuselage of good streamline form, and by a two-bay biplane cellule in which the upper and lower wings are not staggered in relation to each other. The pilot's cockpit is situated just aft of the rear spar of the top plane, from which position he has a good view in nearly all directions. The seat is deep enough to take a seat type of parachute, and is so arranged that it can be raised and lowered easily during flight. The controls incorporate cam quadrants arranged to produce variable gearing between the pilot's controls and the control surfaces. This is achieved by means of cam quadrants in such a way that as the control surface angle increases so an increasingly greater movement is made with the pilot's controls. This arrangement considerably lessens fatigue to the pilot, especially, of course, on nights of long duration. A very full equipment of instruments is provided, as well as guns, ammunition and variable camber gear.
   In the Fleet Air Ann type of III F the rear gunner occupies the third seat, while between him and the pilot, but in the same cockpit as the gunner, is the seat for the wireless operator. Between the two cockpits is a metal partition, in the lower portion of which are mounted an airspeed indicator, altimeter and watch, an arrangement which allows an easy reading to be taken by the occupants of the rear cockpit when lying in a prone position for the purpose of sighting for bomb dropping. In the floor is a trap door below which, in the fuselage bottom fairing, there is a sliding panel which is kept closed when the trap door is closed, thus avoiding the break in the airflow that might occur even when the trap door was closed. The bomb sight for prone bombing is arranged to be mounted on the trap door frame.
   A full-size survey type of camera is mounted centrally towards the rear of the cockpit, a movable trap door being provided in the floor. All types of Fairey III F aircraft are bonded for radio, and every provision is made for the installation of the necessary apparatus. Tapping keys are provided in the pilot's as well as in the rear cockpit. The radio generator is attached to a swinging arm mounted on the starboard side of the cockpit, and is operated by means of a non-reversible worm gear which swings the generator from its stowage position within the cockpit to its outboard position in the air stream.
   The armament consists of two machine guns and a quantity of bombs. The forward gun, operated by the pilot, is of the belt-fed type, while the rear gun, in charge of the gunner, is of the drum-fed type. The front gun is mounted on the port side of the cockpit, and fires through a blast-channel let into the fuselage fairing and engine cowling. The gun sights, which may be of the ring and bead type, or of the "Aldis" type, are mounted on the upper deck fairing of the fuselage immediately in front of the pilot's line of vision. An ammunition box holding 600 rounds is mounted in front of the pilot, and is quickly detachable for refilling.
   The rear gun mounting may be either of the Scarff ring pattern, or the new Fairey-type gun mounting which has been specially designed to meet the requirements arising from the increased performance and manoeuvrability of modern aircraft. Pegs are provided within the rear cockpit for five double drums of ammunition for the rear gun. The new Fairey gun mounting is remarkable on account of the great area of fire which it enables to be covered, and, in addition it is some 15 lbs. lighter than the ring type. Moreover, when not in use the gun stows into a recess in the deck fairing without having to be removed from the mounting; thus the gun, although out of the way and offering no extra resistance, is ready for action at a moment's notice.
   As regards the bomb part of the armament, the Fairey III F is arranged to take various bomb loads as standard equipment. As an example it may be mentioned that a total of two 230-lb. or 250-lb. bombs and four sighter bombs may be carried. Or four 112-lb. bombs and four sighter bombs. Or again, two racks of four 20-lb. bombs can be used, but other arrangements can conveniently be carried out. As a rule, separate release controls are provided for the pilot and bomber, while the fuse levers are so placed as to be within reach of either. All bombs are carried outboard under the lower planes.
   The power plant of a Fairey III F of any type may, as already mentioned, be almost any water-cooled or air-cooled engine of suitable power (450-600 h.p.). In the seaplane exhibited at Olympia it will be a Napier "Lion XI" of 6 to 1 compression ratio. As mentioned previously, the engine mounting is a welded steel tube structure, and a fireproof bulkhead separates the engine from the front part of the fuselage. The fuel system consists of an engine-driven petrol pump delivering fuel to the carburettors through a special design of hand pump, which can be operated instantly by the pilot should necessity arise. The normal fuel tank capacity is 124 gallons, giving a range at cruising speed of approximately 700 miles. If desired "bomb" tanks can be attached in the position under the lower wings normally occupied by bombs, when the range at cruising speed may be extended to about 1,450 miles.
   It is regretted that no performance figures can be published, the Fairey Aviation Company having made it a rule not to do so.
   The second complete Fairey III F to be exhibited will be a two-seater General Purpose type, fitted with an Armstrong Siddeley “Jaguar VI" engine. Apart from the fact that it will be shown as a land plane, and will, as a General Purpose machine, carry somewhat different equipment, such as a spare wheel, desert equipment, etc., this machine is very similar to the seaplane just described, the notes on which will therefore, in the main, serve to describe this type also. The undercarriage is, of course, different, and a few notes dealing with this may be of interest. Of plain Vee-type, with cross axle, the undercarriage of the Fairey III F General Purpose machine makes use of rubber blocks in compression for absorbing the landing shocks, while an oleo damper gear checks bouncing. The rubber blocks are arranged in two columns, one in front of the other, so that the whole leg can be enclosed in a neat streamline fairing. A feature of the oleo damping gear is that an adjustment is provided whereby the amount of damping can be varied to suit local conditions.
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