LIGHT ‘PLANE TYPES THE GRANGER SEMI-TAILLESS HIGH-WING MONOPLANE AN AMATEUR-BUILT MACHINE OF CLEVER AND UNORTHODOX DESIGN
THE ” tailless ” aeroplane is not by any means an entirely recent development in aircraft design, since some of the pioneer machines were of this type, whilst the post-War years have seen sundry experimental craft embodying the tailless arrangement both in Europe and America. As far as this country is concerned, the most notable example of the tailless machine produced in the past decade was Captain Hill’s ” Pterodactyl.” Built in the first instance as a private venture—and constructed, incidentally, under somewhat difficult conditions in the back garden of its designer—this ‘plane showed so much promise in its initial ;test flights, that tlaa, Air Ministry agreed to co-operate with Captain Hill in furthering i t s evolution. That was some years ago, and research work and experiments are still. continuing. Whether the tailless machine will ever vie with
the existing orthodox type is a matter for conjecture, but there is no doubt that the former has definite qualities of its own which are both attractive and encouraging.
The principal feature is its controllability at the stall, and its consequent safety in flight. In the tailless aeroplane the lateral and fore-and-aft controls are all combined in the wing tips, which in the ” Pterodactyl ” are rotatable, so that at whatever angle of incidence the wing may be in flight, the tips with the control surfaces may be moved so as to be effective. Thus, the machine may be pulled up to a steep climbing angle when it will reach the period of the stall, yet, instead of falling in an involuntary dive as would be the case with a normal craft, the wing tips may be set so that the airflow remains even and steady over the directional surfaces,
and control maintained.
Obviously, such an inherent quality as this is of paramount import an c e, while another matter to be considered is that the tailless machine should be cheaper to build. It was these two points which
led the constructors of the machine here described and illustrated to choose a modified form of the tailless arrangement as the basis of their design.
The Granger “Archaeopteryx,” as it is named, differs from Captain Hill’s machine in that the engine (a Bristol “Cherub “) is in front of the pilot, and not placed as a pusher as in the “Pterodactyl.” It also has the rudder placed at the rear of the short fuselage in the usual way, while it has a normal undercarriage. These departures were made with the intention of obtaining a better control on the ground, when taxiing, and it was anticipated that a higher top speed would be secured as a result of its clean lines.
The “Archaeopteryx,” like other tailless types, has a pronounced sweep back to the wing, the span of which is 30 feet.
The wing construction follows normal practice, with spruce spars, and spruce and plywood ribs. The covering is of fabric. The fuselage, too, is wooden, being semi-monocoque in form. The overall length of the machine is 14ft. 10 ins., and the weight (unladen) is 336 lbs. This gives a wing-loading of 5.2 lbs. per square foot.
The arrangement of the wing tips is based on Captain Hill’s layout, their movement . being actuated by a control column, while the ailerons are operated by a wheel (fixed at the top of the joystick), the movement being transmitted by cables. The rudder is worked by pedals, reminiscent of the old Maurice Farman ” Rumpety,” and more recently, the Kegel ” Pruffing ” and “Professor” soarers.
In the air the ” Archaeopteryx ” appears to behave quite well ; the controls are light and nicely balanced, and the landing speed is low. The top speed has not yet been ascertained, but it is believed to be in the neighbourhood of 90 m.p.h.
Altogether a very interesting and original effort, the craft was both designed and built by two amateurs— Mr. R. F. T. Granger and his brother, Mr. J. Granger. Neither has had any engineering training which makes the handiwork all the more commendable. The construction of their ‘plane occupied three and a half years, the work being carried out under difficulties in a small garage.