NEW AEROPLANES

Otago Daily Times, Issue 23055, 4 December 1936, Page 17

NEW AEROPLANES

BUILDING FOR ROYAL AIR FORCE INGENUITY IN DESIGN The new high-wing monoplane, designed and built at the Westland Aircraft Works at Yeovil, will probably be the simplest to produce of all the new types chosen for the R.A.F. (writes the aeronautical correspondent of The Times). It has no stressed skin on the wing or retractable undercarriage to complicate the construction of the wing. The type of construction is different from and superior to anything the company has undertaken before, yet it is at least as easy to arrange and, from the standpoint of the squadrons which will have to maintain the structure, much more convenient. The new aeroplane is an example of obtaining remarkable results without having to demand too much from workshop staffs. The significance of such a type in a period of rapid rearmament needs no emphasis. It promises the two achievements which the public appear most to ' desire—a notable improvement in performance and a relatively high rate of pioduction. These two matters are interrelated, for ingenuity in design has given high aero-dynamic efficiency and has relieved the designer of the need to adventure in fields which throw up large difficulties for the production expert to overcome. The aeroplane is full of novelties, but they are not of the kind which involves a new engineering technique. One indeed took its origin in the benevolent desire to lead the old class of woodworker by an easy path into the world of metal work which is ousting his honourable craft. AERONAUTICAL CURIOSITY The Air Ministry has placed a large order for the new aeroplane, which is to serve the army co-operation squadrons. Delivery dates have been fixed, and the deliveries should be punctual. Subject to the expansion of the works and the provision of extra machine tools to allow of a bigger volume of work within a given period, the transition from the building of an older type of co-operation machine to the building of the new type should be smoothly made. The prospect of so confident a change is a tribute to the new aeroplane, yet if the change had been more difficult the aeroplane would have been worth the trouble. In two respects its wing is an aeronautical curiosity. For the sake of securing a good outlook in all directions from the pilot's seat, the inner sections of the wing as well as the outer are tapered. This should have meant instability at low speeds, and the precise opposite is in fact the Part of the explanations consists in the fitting of automatic slots along the whole of the leading edge of the wing: yet in this matter, too, a gloomy prophecy has been proved unsound. The slots on the inner sections of the wing are connected with the flaps on

the trailing edge, so that the flaps, which steepen the glide, reduce the landing speed and assist at the takeoff, do not operate until the wing is so near stalling that the slots are drawn forward by the disturbed air currents. The theory that the flaps would be insufficiently operated by this device has had no support in practice. Mr H. J. Penrose, the test pilot, took the fully-loaded machine off after a run of 120 yards, landed it, and brought it to rest after a run of 100 yards, and flew it slowly across the aerodrome under full lateral control, with all the slots wide open and the flaps fully depressed. BEST OF ITS TYPE So determinedly stable is this machine that no one yet has succeeded in making it spin. The absence of vice in an aeroplane which may have to be flown slowly for reconnaissance or fire control is important. It is also to be remarked that the speed range is very wide. The combination of high speed which may take it quickly to a scene of operations, with the ability to get into and out of the comparatively small fields which often have to serve as advanced landing grounds makes the machine the best of its type yet produced. It is also the roomiest cooperation aeroplane and is capable of carrying a vast amount of the varied ! equipment which its tasks require. Its crew may fly in comfort and may feel happy about its ability to climb at the angle of a fighter when once it is off th De!ign n and construction have combined with the high output of a Bristol engine to make a big aeroplane fly as fast as only single-seaters have flown in the past. Production may now be able to turn out anew type almost as quickly as in the past it built old types of much smaller dimensions. . . Two fast training aeroplanes, intended to prepare pilots for the, highspeed military aeroplanes they will now have to fly, have lately been constructed for the R.A.F., writes the correspondent elsewhere in the same issue. Both are low-wing monoplanes, and both have ample power at their disposal In both cases the wing loading is fairly high, and flaps on the trailing edges of the wings are used to steepen th# glide and lower the landing speed One of the trainers, that built by the de Havilland Company, is a singieengined type, and the other, a modification of the Airspeed Envoy, is a twin-engined machine. THE NEW ENGINE The new de Havilland aeroplane is. particularly interesting because it is fitted with the new Gipsy Twelve engine a development of the earlier Gipsy types which should yield a maximum output of about 4do h.p. This low-wing monoplane has two seats side by side, for instructor and ! pupil. Its wing span is 47ft sin, and its length 35ft Bin. Its loaded weight is 60001 b. It is thus both bigger and I heavier than the Comet which won the Australia race and which had , i about the same engine power at itsservice. It carries sufficient fuel for , five hours' flying. With a wing area I of 267 square feet, its wing loading amounts to 22.51 b to the square foot. , j

The Airspeed trainer seems to hava been designed to serve three purposes. It has side-by-side seats with dual control for flying instruction, and provision is made for the pupil's controls to be removed when it is desirable to use that place as a bomb aimer's station on bombing practice. The commodious cabin will allow this aeroplane to be used also for navigational instruction, in which cases two pupils will be carried, one in the second pilot's seat and one at a chart table in the cabin. This machine carries a Lewis gun amidships. It was originally intended to fit two Wolseley Scorpio engines, but this trainer will now use two Armstrong Siddeley Chetah (315 h.p.) engines, and . these should give it a top speed of more than 200 miles an hour.