Flight, September 1920

THE AIR MINISTRY SEAPLANE (AMPHIBIAN) COMPETITION

The Fairey III Amphibian Seaplane. 450 h.p. Napier "Lion."

   The machine entered by the Fairey Aviation Co. is similar in general lay-out to the well-known Fairey, Series III, except that the pilot sits aft of the centre section instead of between the planes. The passengers, who are placed side by side, occupy a cockpit aft of that of the pilot. A low wind-screen runs across the deck in front of their cockpit, otherwise they are free to look over the side and enjoy the view. There is no partition between the two bulkheads, the only division between them being the deck fairing.
   The fuselage is a rectangular girder of ash members, covered with fabric except the front portion, which is an aluminium cowl around the Napier engine. The radiators are placed on the sides of the fuselage, and each has mounted on the sides of the body in front of it a hinged shutter, which for maximum cowling lies flat against the side of the body, while for minimum cooling it swings outwards, thus deflecting rather than blanketing the air. A starting handle for the engine projects on the starboard side, and in addition a mechanical starter is fitted, the hand starter being used only in case of breakdowns of the other starter.
   Control is by means of a wheel mounted on a rocking column, and a pedal for the rudder. The camber gear for operating the hinged trailing portion of the wings is in the form of a wheel mounted in the pilot's cockpit. The whole of the trailing edge, including the ailerons, is operated by this wheel, but the ailerons still retain their differential motion. An indicator is fitted which shows the pilot the exact angle that the camber flaps form with the chord line. The retractable land undercarriage which forms part of the amphibian gear is operated by a wheel in the pilot's cockpit.
   The main planes of the Fairey are of the usual Fairey type, having the whole trailing edge hinged so as to form a variable camber. This particular method of cambering the wings is the subject of a Fairey patent. The wings are designed to be folded both for housing and, if desired, when the machine is on the sea. Normally the long main floats extend sufficiently far aft to keep the tail off the water, but when the wings are folded the weight of the wings causes the tail to drop, and the tail float with which the machine is fitted then comes into action. As the wings are braced by external drag cables it becomes necessary to provide some means for quickly casting off these cables when the wings are to be folded, and the manner of doing this is indicated in the accompanying sketches, which show the release devices. The inter-plane struts are in the form of steel tubes enclosed in streamline fairings, and the manner of securing the struts to the spars, as well as the attachment of the lift and anti-lift wires, is shown in one of our sketches.
   The two main floats of the Fairey are of the plain, rectangular section, single-stepped type, with the portion aft of the step extending a considerable distance aft so as to support the tail without the aid of the tail float. When, however, the wings are folded the tail float takes the load, as already mentioned. The main floats are sprung from the cross tubes of the undercarriage by rubber shock-absorbers. When on the sea, the machine has each float sprung both forward and aft. A third shock-absorber is fitted for the land undercarriage, so that when the machine is running over the ground, each side is sprung at three points, providing a form of progressive springing which should make the machine very comfortable to handle ashore.
   The amphibian gear consists of two wheels mounted on a structure of steel tubes. This structure hinges on the front float cross-tube, and its rear horizontal member has its ends resting in slots in the top of the floats. A locking arrangement is provided by means of which the rear tube is secured to a set of shock-absorbers inside the floats. The hooks of this arrangement are operated through cables from the pilot's cockpit, and its details will be clear from the accompanying sketches. The whole land undercarriage forms a rigid unit, its members travelling up and down with the wheels around the pivot formed by the front transverse float tube.

Flight, August 1921

THE FAIREY TYPE IIID SEAPLANE
360 H.P. Rolls-Royce "Eagle" Engine

   IT is a curious fact that in the development of aircraft one comes across, now and then, a type which has survived through a much greater number of years than the vast majority of its contemporaries. This applies, for instance, to such machines as the Avro 504, which, originally designed in 1913, has undergone various slight modifications, but is still very popular in a form not greatly different from that of the 1913 machine. Another instance is the Bristol Fighter, which, although designed a good many years ago, is still considered good enough for the Air Ministry to place a large order with the Bristol Company for machines of this type. Again, take the machine at present under review – the Fairey IIID. The original machine, the type III, which was known in the R.N.A.S. as the N.10, was, we believe, first produced in 1917, and had a 260 h.p. Sunbeam engine. A modification of her, the IIIA, was fitted with land undercarriage, and was used as a ship 'plane and for general purposes. She was, also, we believe, fitted with air bags and hydrovanes and used for experimental purposes for alighting on the sea.
   Later on the wing area was increased, the same fuselage being used, and floats were again fitted, and the machine, still with the 260 h.p. Sunbeam engine, was used as a sea bomber. Finally, came the type IIIC which had a 375 h.p. Rolls-Royce "Eagle" engine, smaller wings and, consequently greater speed than the bomber. This machine was used for reconnaissance work, and became very popular. Modifications of it were built from time to time. Thus the machine which was to have been flown across the Atlantic by Mr. Sydney Pickles was of the IIIC type, but had larger wings so as to be able to carry the extra fuel. Yet another modification was the machine entered for the Schneider Race at Bournemouth in 1919. In this machine the wing area had been reduced to increase the speed, and had the day been a stormy one the Fairey would have been a hard nut to crack for some of the lighter and less seaworthy racers. As it happened the day was absolutely calm, and fog prevented the race from being run.
   The type IIID, which is the one shown in the accompanying illustrations, is a modification of the IIIC, but it is substantially the same machine except for minor alterations. The engine is a Rolls-Royce "Eagle" VIII, mounted in the nose and driving a tractor air screw. The engine is carried on two longitudinal tubular bearers, which rest in turn on three pressed-steel channel-section frames. These frames are of quite thin metal, but by being liberally flanged around all the lightening holes they have been found strong enough when the engine is in place. One of our photographs shows the front portion of the fuselage and these bearers. It may be noticed that the whole front portion of the fuselage, up to a point just behind the engine, is a separate unit, with straight longerons. By undoing a few bolts the entire engine unit can be removed en bloc from the machine. The manner in which this is accomplished is illustrated in one of our sketches. The sketches show the joint in the lower longeron. The joint in the top longeron is similar, except that there is, of course, no fork for wing attachments. The joint between the two parts of the longeron is made of a spool, machined out of the solid steel, and having holes for the many different members which meet at this point. Into the hollow centre of this spool is fitted the forked support for the lower front spar, as indicated in the sketch. The ends of the longerons are provided with light sheet-steel shoes, and fish plates, shaped as shown, are bolted through the longeron and through the holes in the spool. About twelve different members meet at this point, and it would be difficult to conceive of a neater way of joining all these. Yet in a later type, which is now being built, and is, in fact, similar to the machine shown at the last Olympia Aero Show, an even neater joint is provided. This is mainly the result of making the main framework of this part of the fuselage of steel tubing, but as the machine is an experimental one, we may not refer to this point in detail. The upper and lower joints are connected by a slightly sloping steel tube, which is, however, afterwards protected , by a wood fairing so as to afford means of attaching the covering.
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The Controls, Etc.

   THE standard part of the controls is in the form of a wheel for elevator and ailerons and a foot bar for the rudder. In all Fairey machines, however, wing flap gear is incorporated, and this necessitates some additional control organs. Briefly speaking, the Fairey camber gear consists in pulling down or raising the entire trailing portion of the wings, from the rear spar to the trailing edge, at the same time retaining the differential movement of the ailerons. The manner of accomplishing this is indicated in one of our diagrams. The trailing edge of the planes is hinged throughout the entire length, and the wiring so arranged that the trailing edge is pulled down against the action of rubber cords. A reference to the diagram will make the principle clear. Mounted on a left and right hand worm in the fuselage are two internally threaded fittings which are caused, by rotation of the worm, to travel inwards or outwards. To these fittings are attached the inner ends of the flap cables, which run over pulleys on the lower front spar and from these back to the lower plane flap cranks. Thus when the worm is so rotated that the fittings travel inwards, the cables are pulled inwards as well, pulling down the lower plane flaps. From these, cables run to the trailing edges of the upper flaps and to the upper cranks, pulling down the top flaps with the lower ones. From the upper flap cranks cables run over pulleys on the top front spar, and back to rubber cords attached at their other end to the top rear spar. It will be seen that these rubber cords take the place of return cables, pulling up the flaps when the positive cables are paid out. The ailerons are pulled down with the rest of the trailing edge by means of cables passing from the pulleys on the worm fittings to the aileron cranks on the lower plane. The lateral travel of these pulleys does not affect, or to a very small extent only, the length of the diagonal cable operating the aileron. It will be seen that although the ailerons are pulled down or up with the flap, their differential action is not interfered with, so long as the flaps are not down to the limit of their travel. The worm in the fuselage is operated by means of a wheel on the starboard side of the pilot's cockpit. In addition to the camber wheel, there is another and smaller wheel operating the setting of the tail plane so as to maintain the trim of the machine. In our diagram this wheel has been omitted for the sake of clearness.
   The Fairey Patent camber gear is extremely simple, and in practice it has been found to give very good results, materially lowering the landing speed of the machine. We have no data as to the actual lift coefficient attained with this gear, but an approximate estimate indicates a maximum lift coefficient of close upon 0-9 absolute. Consequently a fairly high wing loading can be employed without raising the alighting speed to a prohibitive figure.
   The following is a brief specification of the machine: Span 46 ft. 1 1/4 in. Chord 5 ft. 6 ins. Gap 5 ft. 7 ins. Overall length 36 ft. 1 in. Area of main planes, 500 sq. ft. Weight fully loaded 5,050 lbs. Petrol capacity 105 gallons. Oil capacity 8 gallons. Useful load 1,060 lbs. Performance: Top speed 96 knots. Climb 5,000 ft. in 6 mins. 40 secs. Ceiling 17,000 ft.

Flight, January 1922

THE NEW FAIREY LONG-DISTANCE SEAPLANE
Rolls-Royce "Eagle" Engine

   IN our last issue we recorded briefly that a new Fairey seaplane had succeeded in carrying a useful load of over 3,000 lbs. with one Rolls-Royce engine. Taking the power of the "Eagle'' as 375 h.p., the useful load carried was over 8 lbs./h.p., which is an extraordinarily good figure, and one which, incidentally, promises well for the future of commercial aviation. In war type of machines the useful load was frequently so small as to leave no margin, but as we get away from the war type and learn more about the commercial type, the increase in useful load per horse-power expended tends to show that it is only a matter of development to reach a point where a very considerable margin of useful load exists, which can be used for carrying passengers, goods, etc. Although the Fairey seaplane is not a commercial type, in the ordinary sense of the word, it will be useful to regard it in this light, specially as nothing may be said about the purpose for which the machine is actually intended.
   The machine is well shown in the accompanying photographs. In its general lines it resembles the famous "C.III's," although naturally its proportions are quite different. The wings, it will be seen, are of very much, larger span than those of the “C.III," measuring in fact 62 ft. from tip to tip. The overall length is 36 ft. 6 ins., as compared with just over 36 ft. for the "C.IIID." Thus the length has scarcely been increased at all, the fuselage being practically that of the standard "IIID." The floats are somewhat larger, to support the extra load, but otherwise the machine is, in the main, a standard fuselage fitted with large wings. The Fairey Patent camber gear is, of course, incorporated, and this probably accounts in a great measure for the fact that the machine gets off well with such a heavy load.
   It has already been mentioned that we are not at liberty to state the exact purpose for which the machine has been built, but it is not without interest to note that the machine was sold under a firm guarantee to carry out the stipulated performance within four months from the date of the order, so that it had to be designed, built and tested within that period. That the machine not only reached, but actually slightly surpassed, the calculated performance will not come as a surprise to those who know the Fairey designing staff, but it is a fine achievement nevertheless. The top speed developed was 95 rn.p.h., with a power loading of over 19 lbs./h.p. and a wing loading of over 10 lbs./sq. ft. Naturally the climb, with such loadings, was not spectacular, but it reached 350 ft./min. in the earlier stages, which is certainly better than one would expect, again probably due to the camber gear. The landing speed was 42 knots, which would appear to give a very high lift coefficient, although some of the lift at large angles is, of course, due to other parts than the wings. As stated last week, the weight of the machine empty was 4,150 lbs. and the useful load 3,100 lbs., bringing the total loaded weight up to 7,250 lbs. Probably this is the greatest weight ever lifted by a single Rolls-Royce "Eagle."
   It is interesting to speculate on the possibilities of a similar machine, intended for commercial work and fitted with a wheel undercarriage. The saving in weight would be very considerable. We have no figures relating to the weight of the floats, but let us assume that the land undercarriage would be 300 lbs. lighter than the floats. The useful load would then become 3,400 lbs., which could be divided into any desired proportion of fuel and paying load. If we assume four hours' fuel, the remaining available load would be approximately 2,500 lbs. After deducting the weight of crew, with their paraphernalia, there would still be close on one ton available load left, which is surely approximating to a record for a machine fitted with an engine of 375 h.p. only. And even at that, the maximum speed is 95 m.p.h. with full load. This would appear to be sufficient for work on most "airways," although running the engine "all out" normally, would not tend to give it a long life. By slightly reducing the useful load, however, the engine could be "nursed" once the machine was off the ground, and its life correspondingly increased. Such a machine should prove extremely useful, for instance as a goods' carrier. This would mean enlarging the fuselage somewhat, but this need not entail any very great increase in structure weight, nor in resistance.
   Altogether the achievement is one of which the Fairey Aviation Company may well be proud, and when, in the near future, we come to use specialised types instead of "general utility" machines, the firm should be in a position to supply extremely economical machines somewhat of this type.

Flight, July 1923

Gothenburg International Aero Exhibition 1923

THE MACHINES

Fairey Aviation Company, Ltd., Hayes, Middlesex

   THE Fairey exhibit at Gothenburg is a Series IIID Seaplane. While they are prevented from showing their latest types of aircraft, it should be pointed out that the Series III is still in production as a Service type - an order for some of these machines being in hand at the present moment. In case our readers should think this is an old type of machine we might add that the IIID is the fastest type of the Series III - which has, modified from time to time, given such excellent service since the first of the type was designed in 1917 - incorporating all modern modifications and constructional improvements.
   That this machine is up to modern requirements is borne out when we state that by the latest test the Series IIID, fitted with a 450 h.p. Napier "Lion," has a top speed of 116 m.p.h. at 12,000 ft., a ceiling of 18,000 ft. with full load, a rate of climb of 1,300 ft. per min. at sea level, and 600 ft. per min. at 10,000 ft., carrying a total useful load of 1,650 lbs.
   This machine can be converted from a seaplane to a land machine, or deck type, and the Fairey Oleo-pneumatic chassis employed for this purpose is also shown.
   The Fairey Series III is a tractor fuselage biplane of some 46 ft. wing span, and when used as a seaplane is fitted with twin floats of the latest Fairey design, which are constructed after boat-building practice.
   The principal feature of this machine - as with all other Fairey types - is in the patent variable camber gear. This is an extremely simple and effective device, consisting of an arrangement, worked by cables from the pilot's cockpit, for pulling down the entire trailing edge of the wings and thereby increasing the camber and consequently the lift. The whole trailing portion of the wing, from the rear spar to the trailing edge, is hinged, the outer portions, at the tips, being separate from the rest, so that the differential aileron movement is retained at the same time. In other words, the ailerons function as usual with the flap at any position. The effect of this arrangement, which has proved very satisfactory in practice, is to allow of a considerably higher wing loading without any increase in the landing speed.
   Apart from the flap gear the wing construction more or less follows standard practice. The wings are made to fold back, vertical pins in the rear spar fitting forming the pivots. The fuselage is of the usual rectangular girder construction, with ash longerons and struts in front and spruce members aft. The longerons are straight, and do not taper, with the result that the fittings are identical throughout the greater part of the fuselage.
   The tail is of the trimming type, with divided elevators. The rudder, of ample proportions, is balanced, and a large vertical fin is mounted in front.
   The pilot's cockpit is located forward between the planes, and immediately behind him, well back of the planes, is the gunner's compartment, which is large and roomy.