Flight, December 1928

THE ELIAS "AIRCOUPE“
An American Medium-Powered Commercial Monoplane

   IN designing the Elias "Aircoupe," Joseph L. Cato - who, by the way, produced a very interesting little sporting parasol monoplane as far back as 1919 - not only did so in accordance with the U.S. Department of Commerce regulations as they stand today, but looked a little ahead and embodied features with a view to meeting requirements of the future.
   The "Aircoupe," which is constructed by G. Elias & Bro., Inc. of Buffalo, N.Y., is not classed by its producers as a light 'plane in the sense in which this class of machine has been known in America until recently. It is intended to be a commercial machine of medium size and power but with a high performance. It is, however, in every way suitable for light 'plane work, such as clubs, flying schools, and the private owner, as well as for business or sporting purposes.
   It is a braced high-wing, or "parasol," monoplane, and is produced in two models - one with an open cockpit, and the other with an enclosed "coupe"; it is, however, readily convertible from one type to the other. Safety has been the first consideration in the design of this machine. It has an exceptionally flat gliding angle, low landing speed, and instantaneous response to the controls at all speeds. High factors of safety have, it is claimed, been maintained at all points, while the landing gear is both wide and strong. Another feature is that every important fitting is in sight and easily inspected.
   Attention has also been given to the comfort of pilot and passenger, who sit side by side in well-upholstered seats in a roomy, well-ventilated cabin with plenty of leg room. Unobstructed vision - except perhaps immediately overhead – is obtained through laminated safety glass windows in front and large sliding windows in the doors each side.
   The fuselage being low, entrance and exit can be made with ease through these doors on each side - with as much ease and comfort, in fact, as with a motor-car. At the rear of the cabin, on top of the fuselage, is a compartment for small parcels, and this can be loaded or emptied quite easily from outside, through the cabin door.
   As regards performance, the "Aircoupe," equipped with an 80 h.p. Anzani, has a maximum speed of about 90 m.p.h., and a landing speed of about 30 m.p.h. Its climb is 3,600 ft. in 10 mins., while the service ceiling is 10,000 ft. The takeoff, in dead calm, is within 125 ft., and on landing the run before coming to rest is about 100 ft.
   The main constructional features are as follows. The fuselage is of welded chrome-molybdenum steel tube construction, without bracing wires. The engine mount is of similar construction, so designed that all parts of the power plant are easily accessible ; the engine can be dismounted by removing six bolts. Immediately behind the engine is a fire wall. High-grade fabric is employed for the covering of the fuselage.
   The wings are of the "semi-cantilever" type, having two lift struts, each side extending from the bottom of the fuselage up to the wings. These struts, it should be noted, do not attach to fittings welded to the fuselage, but are directly attached to tie rods running through the fuselage inside a heavy-gauge steel tube, which also serves as a compression member.
   This method of attaching the lift struts eliminates any danger of fitting failure at the fuselage through crystallising due to vibration. The upper ends of the struts are also fitted with universal fittings, cut from solid nickel steel forgings, heat-treated to 125,000 T.S., bearing on aluminium pads on the underside of the spars. This allows the inverted load to be taken on the under side of the spar, rather than on the bolts that hold in place the side plates carrying the lift loads. The side plates are made from chrome-molybdenum steel, heat-treated to 150,000 T.S.
   The wings are constructed of wood with non-routed spruce spars, and the rib webbing is of plywood with spruce cap strips; the entering and trailing edges are of duralumin. The roots of the wing spars are connected together over the fuselage with two 5/8 in. heat-treated nickel steel "T" bolts, sufficiently large to provide proper bearing surface for the cabane struts. The latter comprise two pyramids of four struts each mounted on the top longerons of the fuselage. The internal drag or drift wires are 10-32 tie rods for the two inner bays and 6-40 for the outer bay or wing tip section.
   The horizontal stabiliser is non-adjustable - no adjustment is required as the entire useful load is carried near the c.g., and light or heavy loads do not interfere with the balance of the machine. The vertical fin, however, can be adjusted on the ground, to take up any engine torque. All control surface frames are of welded steel tubing, covered with fabric. Stick and rudder pedal control is employed, all pulleys being of bakelite composition and visible for inspection. The entire control system operates very lightly, and is so designed. that all slack can always readily be taken up.
   The landing gear is of the non-axle type, with wide track (7 ft. 6 in.). The shock absorber is of special design, and is particularly durable and strong, there being no rubber to decay, air pressure to maintain, and no glands that need attention. The load is taken by a steel coil spring, and bouncing is prevented by hydraulic cylinders. The tail skid swivels in the rudder post through 180°, and is steerable if desired. All working parts are located outside the fuselage, and can easily be inspected.
   The fuel tank is located above the wings over the fuselage, giving full gravity feed to the carburettor, even at extreme angles of flight. Sufficient fuel is carried for four hours at cruising speed. Flexible tubing connections are used for joints, and large size copper tubing, properly annealed after forming, is employed.
   The main characteristics of the "Aircoupe" are :-
   Span 28 ft. 1 1/2 in.
   Chord 7 ft. 0 in.
   Length overall 20 ft. 11 in.
   Height overall 7 ft. 2 in.
   Wing area 192 sq. ft.
   Area of ailerons 20-4 sq.ft.
   Area of tail plane 13-2 sq.ft.
   Area of elevators 13 sq. ft.
   Area of fin 3-6 ft.
   Area of rudder 6-5 sq. ft.
   Weight empty 870 lbs.
   Weight loaded 1,334 lbs.
   Weight per sq. ft. 7 lbs.
   Weight per horse-power 16-6 lbs.
   Speed range 30-90 m.p.h.
   Climb at sea level 590 ft./min.
   Ceiling 10,000 ft.
   Fuel consumption (80 m.p.h.) 5 gals./hour.
   Oil consumption -4 gal./hour.