Flight, September 1920

THE "PIONEER" SINGLE-SEATER SPORTPLANE

   TRIAL flights were carried out a short time back, at Long Island, N. Y., with a small single-seater sportplane constructed by the Pioneer Aircraft Corp., and we give herewith a few particulars, together with scale drawings and illustrations of this machine. The "Pioneer" was designed by the above company's engineer, Harry Herzog, primarily as a sporting cross-country model, selling at $2,000, but it is also suitable for commercial work, such as mail and light freight work, advertising or exhibition flying.
   During its first trials - which were carried out by Lieut. Bruce Eytinge, late R.A.F. - it demonstrated good flying qualities, being very stable and easy on the controls. It had a fast climb, quick take-off, and an exceptionally flat gliding angle, whilst its landing speed was as low as 25 m.p.h. The average run after first touching the ground was only 60 ft. - no braking devices or skids being employed. The range of action at cruising speed (40 m.p.h.) is 2 1/2 hrs., the petrol consumption being 4 gals, per hour. These qualities, together with its small size and light weight, render it eminently suitable as a sporting one-man 'plane.
   The "Pioneer" Sportplane is a tractor biplane, fitted with a 40 h.p. 4-cyl. vertical, 8 valve-in-head water-cooled "Pioneer" engine, and having a span of 24 ft., and an overall length and height of 15 ft. 6 ins. and 6 ft. 9 ins., respectively. The main planes are of equal span top and bottom, and are built up in four sections, the two top ones, which are without dihedral angle, being mounted a short distance above the fuselage on a pylon of inverted V-struts, and the lower sections, which are set at a dihedral angle of 6°, are. attached to the lower longerons of the fuselage. The top plane is staggered forward 5 ins., and is separated from the lower by a pair of streamlined interplane struts each side of the fuselage. An extra pair of tubular struts is located near each wing tip. Ailerons are fitted to the top plane only. The wings are set at an angle of incidence: of 6°.
   The tail groupe is, to a certain extent, unusual, in that two rudders are employed, and its distance from the main planes is extremely short. The horizontal stabilising surface is, however, of large proportions, and is of the double cambered type, set at 0° incidence in the line of thrust. The elevators are also large, and are, as usual, hinged to the trailing edge of the tailplane. The two balanced rudders are located at the end of each side of the fuselage, and are hinged to triangular vertical fins, mounted above and below the fuselage. Under each rudder is fitted a tail skid.
   The fuselage, which is comparatively wide and deep (max. 2 ft. and 3 ft., respectively), is of rectangular cross section, fairly well streamlined, tapering to a horizontal knife-edge at the stern. It is of three-ply veneer construction throughout.
   The engine is carried on bearers supported by the first and second transverse bulkheads, which are of sheet steel. Mounted on the top of the second bulkhead is the radiator, which is also anchored to the leading edge of the top plane. Another method of mounting the radiator may be seen in one of the accompanying illustrations, where two long units are mounted on each side of the fuselage. The pilot's cockpit is comfortable and roomy, and is located at the trailing edge of the planes ; where a very good view in all directions is obtained. The control is of the stick and rudder bar type, and in front of the pilot is an instrument board containing an engine revolution counter, altimeter, oil-gauge, water temperature gauge, and ignition switch. The engine is well balanced, and gives little, if any, vibration, and weighs 150 lb. It drives a Paragon tractor screw, 5 ft. pitch by 6 ft. 6 ins. diameter, direct at 1,500 r.p.m. Atwater-Kent battery ignition is employed, and the lubrication is by splash feed and a constant spray by means of a spur-gear oil pump. A Zenith carburettor is fitted, petrol being fed by gravity from the 10-gal. tank located between the pilot and the engine, and separated from the latter by a fireproof asbestos wall.
   The landing chassis is of the ordinary V-type, and calls for no special comment. We understand the construction and workmanship of this little machine is of high quality, and a factor of safety of 8 is employed.
   The general characteristics of the "Pioneer" Sportplane are :-
   Span 24 ft.
   Chord 4 ft.
   Gap 3 ft. 3 ins. to 3 ft. 8 ins.
   Stagger 5 ins.
   Overall length 14 ft. 6 ins.
   Overall height 6 ft. 9 ins.
   Area of main planes 166 sq. ft.
   Weight (empty) 480 lb.
   Weight (fully loaded) 800 lb.
   Speed range 25-70 m.p.h.
   Radius of action 2 1/2 hrs.
   Loading per sq. ft. 4-8 lb.
   The machine in Loading per h.p. 20 lb.
   Engine, 40 h.p. "Pioneer" 4-cyl. vert.