Flight, June 1929

BRITISH AIRCRAFT AT OLYMPIA

S. E. SAUNDERS, LTD.

   THE firm of S. E. Saunders is known throughout the world as pioneers of high-speed surface vessels, while the experience of the firm in marine aircraft goes back to 1912. Recently, Sir A. V. Roe and Mr. John Lord became financially interested in the company, and a vigorous policy was at once laid down, one of the first results of which is the little four-seater flying-boat, which is to be exhibited at Olympia.
   The "Cutty Sark," as the Saunders' four-seater flying-boat has been christened, is a more than usually interesting machine, not only because it represents a type of aircraft likely to become extremely popular during the next few years, but also because it combines what may be termed the two extremes in aircraft construction: all-metal and all-wood. The flying-boat hull is built entirely of Duralumin, or rather "Alclad," while the wing is a wooden structure, with three-ply wood skin or planking. This form of wing construction has been used by Fokker for years, and has been proved satisfactory, both for cheap production and for durability with but little attention.
   The boat hull of the Saunders' "Cutty Sark" is of a type developed by this firm during the last few years, and is claimed to possess remarkably low water resistance. It differs from the hulls of larger flying-boats, in that it has but a single step, situated a short distance aft of the centre of gravity of the machine. The Vee bottom extends aft of the step, and at the sternpost the keel sweeps down slightly. Constructionally, the hull consists of frames of "Z" section, to which the planking plates are riveted. The use of "Z" sections in the frames greatly facilitates riveting, as the riveting tools can be brought against the rivets at right angles to the frame flanges. Approximately half-way between keel and chines runs, on each side, a deep fore and aft member or stringer, which is so arranged that it transmits the loads from the planing bottom to the gunwales, and thereby to the whole hull. This form of construction is not only cheap, but should be very strong. It avoids the need for panel beating, always rather a costly and laborious process, and in the "Cutty Sark" the only parts requiring this treatment are the chines and one or two plates in the extreme bows of the hull. Model tests in the tank have indicated that the hull shape is to be regarded as good, so that it would appear that we have here a form of construction which combines cheapness with hydrodynamic efficiency.
   The cabin of the "Cutty Sark" is exceptionally roomy, and as it has windows on all but the aft side, it is unusually light and airy in appearance. The side windows are made to open, as is also the starboard half of the roof window, and a triangular window above the instrument board. Thus, ventilation should present no problems, while the triangular window should enable the pilot to pick up his moorings without going forward in the hull, where a mooring hatch is provided. The four seats are very comfortable, and the cabin gives ample room for legs and elbows, so that even on very long flights the occupants are unlikely to suffer any undue fatigue. The cabin is ahead of the wing and engines and thus not in the slipstream, and, consequently, but little should be heard of the engine noise. In this respect, the "Cutty Sark" comes nearer to the comfort of the "pusher" machines of the old days than anything we have seen, and with the added protection of a cabin. In fact, it would be almost impossible to imagine a lay-out more likely to give a maximum of comfort.
   The pilot's seat is the port forward one, and beside it is a seat for another pilot, or for a passenger, dual controls being provided. When not needed, the starboard controls can be removed. This arrangement has much to recommend it, not least its obvious suitability for instructional work, and as the time is undoubtedly coming when the flying-boat will be extensively used on our long Empire air routes, it would appear that among its other uses the "Cutty Sark" might form a very excellent training and practice machine for seaplane pilots. The fact that the machine is fitted with two engines would reasonably simulate conditions on a larger flying-boat.
   The one-piece monoplane wing rests direct on the gunwales of the boat hull, and the two A.D.C. "Hermes" engines are mounted on steel struts above the wing, each engine being a readily detachable unit with its mounting. The main petrol tanks are housed inside the wing, and in the fairing behind each engine is a small gravity tank, separated from the engine by a fireproof baffle. As the crew can walk the wing, the engines are remarkably accessible.
   Lateral stability on the water is obtained by two outboard floats of large volume, and it is of interest to note that should the main hull spring a leak and become partly flooded, the machine would probably sit nearly upright on the water, supported by these two floats. While, in case of total flooding of the main hull, the wooden wing has been made watertight (and divided into a large number of compartments), and would support the machine for a very long period. Thus, the "Cutty Sark" should be one of the safest aircraft imaginable.
   The space inside the hull is unobstructed, and a large quantity of luggage or mails can readily be stowed away there. One could suggest dozens of uses to which a machine of this type could be put, but space forbids. As a really comfortable "air yacht," the "Cutty Sark" would be difficult to beat, while for passenger work on a small scale, seaside joy riding, and as already mentioned, training of seaplane pilots for larger flying-boats, the machine appears to have obvious claims to attention.
   The main dimensions and areas of the "Cutty Sark" are as follows :- Length, overall, 34 ft. 4 in.; wing span, 45 ft.; overall height, 11 ft. 2 in.; wing area, 320 sq. ft.; area of tail plane and elevator, 36 sq. ft.; area of fin and rudder, 20 sq. ft.
   The show machine will be fitted with two A.D.C. "Hermes" engines, but it is pointed out that, within reason, any engines giving a total of about 200 h.p. may be used. For instance, should three engines be preferred, one presumes that the A.B.C. "Hornet," or the Pobjoy types, would be suitable.
   Fitted with the "Hermes" engines, the "Cutty Sark" has a tare weight of 2,375 lbs., and a permissible gross weight within the C. of A. of 3,500 lbs. The normal weight of fuel and oil (for 4 hrs.) is 365 lbs., leaving a normal weight of pilot, passengers and luggage, of 760 lbs. Assuming that the pilot weighs 160 lbs., the pay load is 600 lbs., or nearly 3 lbs./h.p. Looked at in another way, the expenditure of power is 70 h.p. per paying passenger, or 52-5 h.p. per occupant. The estimated top speed is 105 m.p.h., and the cruising speed 85 m.p.h.

Flight, April 1930

AIRCRAFT FOR THE PRIVATE OWNER

CUTTY SARK

   SAROS' Cutty Sark is the only flying machine of its kind at present manufactured in England. As a private owner's machine, it comes into the class which caters for people who want a machine capable, of carrying four people and it is built by Saunders-Roe at Cowes.
   As a flying-boat it is unique in its construction, being a combination of metal and wood. The hull is built entirely of "Alclad." This is duralumin protected on the outside with a coating of pure aluminium which acts as a very good protection against corrosion. Fitted with two "Cirrus-Hermes" engines, it has a good performance, and in its latest version it should have a wide appeal to those who wish to travel widely in their machines. The wing structure is plywood, and is divided into many watertight compartments, so that in the case of a crash when the hull becomes waterlogged, the wing tip floats would keep the machine above water, and should they fail, the wing itself would support the whole machine for a very long time.
   A further development which should even more widen its appeal is the fitting of an amphibian undercarriage. With this undercarriage, which allows it to land on aerodromes or on the water, the "Cutty Sark" must be considered as the air-yacht par excellence.
   The seats are arranged in pairs and dual controls are provided for the front pair, so that the "Cutty Sark" might well be used for instructional work for seaplane pilots, or in any case as a private owner's machine it will have the advantage of a reserve pilot being able to take over the controls for a spell. Further developments of this machine are being planned in the "Windhover" and the "Cloud." Both these are really in the luxury class for private owners, but for the man who can afford them they should be among the best in their class. The former is a three-engined version with a cabin accommodating five persons, while the latter is a 6-8 seater, with two larger engines.
   All of these can be fitted with the amphibian undercarriage, and if they follow out the promise offered as developments of the "Cutty Sark," they should prove a type for which we have been waiting for some time.

Flight, November 1932

British Aircraft

Saunders-Roe, Limited
Cowes, Isle of Wight

   FROM the time Sir Alliott V. Roe and Mr. John Lord joined forces with Mr. H. E. Saunders, the firm of Saunders-Roe has pursued a vigorous policy of flying-boat development. During a period of a few years no less than four distinct types of flying boat have been produced, of which three are civil types, the fourth a military machine.

"Cutty Sark," "Windhover" and "Cloud"

   The family of civil flying boats includes the above three, the "Cutty Sark" being the smallest and the "Cloud" the largest. In the structural methods adopted the three machines are similar, with "Alclad"-covered metal hull and plywood-covered wooden wing.
   The "Cutty Sark" is a small four-seater amphibian flying boat, with two Armstrong-Siddeley Genet Major engines (Gipsy II, Gipsy III and Hermes IV are optional alternatives). The engines are placed on struts above the wing, where they are very accessible, and where the propellers are well clear of water spray.
   As a plain flying boat, with the Genet Major engines, the "Cutty Sark" has the following characteristics:
   Length o.a 34 ft. 4 in. (10,45 m.)
   Wing span 45 ft. (13,7 m.)
   Wing area 320 sq. ft. (29,7 m2.)
   Tare weight 2,555 lb. (1 160 kg.)
   Pay load 850 lb. (386 kg.)
   Gross weight 3,997 lb. (1 817 kg.)

Flight, April 1936

MODERN LIGHT AIRCRAFT REVIEW

SARO CUTTY SARK

   IT has often been a source of wonder that more amateur pilots have not interested themselves in the seaplane, and, to particularise, in the small amphibian. The fact that there is only one type of amphibian on the British market is neither here nor there, since the demand would automatically have produced the supply in due course. The performance of the amphibian must naturally be down on the straightforward machine, both in the matter of payload and speed, but one or two recent designs have shown us that the difference need not be so very great.
   However, for the present the Saro Cutty Sark - or, perhaps, the larger Cloud - are the only machines of this type available, and each of these has been on the market for a number of years. Naturally, if the demand was present, Saunders-Roe could now improve considerably on these designs. So far as we know, only two Cutty Sarks are in use in this country, though the Cloud has been adopted by the Air Ministry for training purposes. The former, fitted with two Gipsy Major engines, has, however, been adopted by a foreign Government for coastal reconnaissance duties, and in this form the Sark has a very good performance.
   The cabin seats four in two pairs, while there is a luggage compartment under the cantilever wing and the locker in the nose for nautical gear. Dual control can be fitted and the two centre panels of the screen hinge back to obtain access to the forward compartment and to enable one of the crew to deal with moorings, and so on.
   The specification of the Cutty Sark when fitted with two Gipsy Major engines and when equipped as an amphibian is as follows: Weight empty, 2,670 lb.; disposable load, 1.180 lb.; span, 45ft.; length, 34.3 ft.; maximum speed, 107 m.p.h.; cruising speed, 90 m.p.h.; initial climb, 500 ft./min.; endurance, 3.5 hr. Makers: Saunders-Roe, Ltd., East Cowes, Isle of Wight.