Flight, June 14, 1917.
THE BURGESS "B.P." PRIMARY TRAINING
IN order to meet the requirements of the U.S. Army for a machine for the primary training of pilots, W. Starling Burgess, of the Burgess Co., Marblehead, Mass., U.S.A., designed the tractor biplane described and illustrated herewith. The main characteristic of this machine is in the seating arrangement, the instructor and pupil being seated side by side - an arrangement which is preferred by some instructors.
The extra width of the fuselage at the cockpit due to this seating arrangement is by no means excessive, and, indirectly, is the means of producing a fuselage of nearly perfect streamline form. The general appearance is also added to as a result of this larger width.
Another noticeable feature is in the arrangement of the interplane struts. These are not only inclined forward, as a result of staggering the top plane, but they are also inclined outwards - a practice common with several types of Austrian machines. It will also be noticed that they are inclined outwards at angles which increase from the innermost to the outermost struts.
Throughout the whole machine, simplicity of construction, combined with strength, have been the two considerations that have received the designer's attention, and in both experimental and official trials the machine gave very satisfactory results. The large plane area, 437 sq. ft., and the wing section, R.A.F. 3, render the machine comparatively slow and easy for the pupil to handle.
Both top and bottom planes are in two sections each, the top joined at the centre, and the bottom attached to the fuselage. The dihedral angle of both planes is 3/4 ° and the angle of incidence is 1 1/4°. The top plane is staggered forward 1 ft. 9 ins. The main spars are spaced 4 ft. apart, the forward spar being located 9 ins. from the leading edge. The attachment of the interplane struts occurs at the following distances from the centre :- Fuselage struts, 2 ft. 8 ins.; middle struts, 9 ft. 1 1/2 ins. (top), 7 ft. 2 ins. (bottom); outer struts, 16 ft. 9 ins. (top), 14 ft. 5 ins. (bottom). The wing-tips are raked 16°. Ailerons, of 18 sq. ft. area each, are hinged to the rear spar of top plane only. The area of the top plane, excluding ailerons, is 219 sq. ft., and that of the lower plane 182 sq. ft.
The tail surfaces, which are of somewhat ample proportions, consist of a stabilising plane in two sections, mounted one on each side of the fuselage, having elevator flaps hinged to the trailing edge. A balanced rudder is pivoted on the tubular stern post, and in front is a triangular vertical fin. The stabilizer is supported at its forward end by tubular struts.
The fuselage is of rectangular section tapering to a vertical knife-edge at the rear. The length from the nose to stern post is 21 ft. 2 ins. The maximum width and depth, at cockpit, is 4 ft. and 2 ft. 6 ins. (3 ft. 7 ins. over turtle deck) respectively. The top longerons are parallel to, and 7 ins. above, the line of thrust. Mounted in the nose, in front of the engine, is the radiator, measuring 2 ft. 2 ins. high by 2 ft. 3 ins. wide.
The landing chassis is of the three-wheel type, all three being 26 ins. by 3 ins. disc. The two main wheels are mounted on a tubular axle, running in metal guides and carried by two pairs of tubular steel V-struts. The forward wheel is rigidly supported below the nose of the fuselage by a pair of tubular steel struts. The latter, together with the forward members of the V-struts, are provided with wood streamline fairings. A pair of horizontal tie-rods also connect the front wheel and the main axle.
The general dimensions are as follows :- Span, top 41 ft. 6 ins., bottom 34 ft.; chord, 6 ft. 6 ins.; gap, 6 ft.; stagger, 1 ft. 9 ins.; supporting surface, 437 sq. ft.; overall length, 23 ft. 11 ins.