The 1909 R. E. P. monoplane was considered by many to be one of the most perfect types of aeroplanes. Great finish was exhibited in its construction and form, but due probably to motor troubles it never was flown for any great length of time. M. Pelterie, the designer, was one of the foremost aviation scientists of the era, and previous to his experience with this machine he had conducted a series of gliding experiments of great interest.
Top Speed: 39 m.p.h.
Engine: 7-cylinder 35 horse-power R. E. P.
Wingspan: 30 feet
Weight: 900 pounds
Specifications from “Monoplanes and Biplanes,” by Grover Loening, 1911
The Frame
The central frame, somewhat similar in shape to a bird’s body, was made largely of steel tubing, and was quite short. All exposed parts were covered with Continental cloth.
The Main Wing
The main surface was particularly strong and solid, and was made of steel tubing carrying wooden ribs covered with Continental cloth. The curvature was very similar to that of a bird’s wing, and transversely the surface curved downward dihedrally from the center. There was very little bracing necessary. The spread was 30 feet, the depth 6.1 feet, and the area 214 square feet.
The Direction Rudder
The rudder for steering from side to side consisted of a vertical rectangular surface of 8 square foot area, placed below the central frame at the rear. It was operated by the side-to-side motion of the lever at the aviator’s right hand. To turn to any side the lever was inclined to that side.
The Elevation Control.-There was no elevation rudder in the 1909 Pelterie monoplane, the elevation of the machine being regulated by changing the incidence of the main plane itself. To ascend, for example, the aviator pulled the lever in his left hand toward him. This increased the incident angle of the plane and the consequent increase of lift caused the machine to rise.
Roll Control
Each half of the main plane was warpable about its base, and transverse equilibrium was obtained by an inverse warping of the plane. The side-to-side motion of the left- hand lever controlled the warping. If the machine was tipped down on the right end the lever was moved to the left and the machine brought back to an even keel. In turning to either side both the left-hand lever controlling the warping and the right-hand lever controlling the direction rudder were simultaneously moved to that side. This was a very effective controlling system.
Keel
Vertical and horizontal keels, consisting of gradually tapering surfaces, were fixed to the frame and aided in preserving stability. The rear horizontal keel, shaped like a bird’s tail, had an area of 20 square feet.
Propulsion
A 7-cylinder 35 horse-power R. E. P. motor, placed at the front, drove direct a four-bladed aluminum and steel propeller at 900 r.p.m. The diameter of the propeller was 6.6 feet, and the pitch 5 feet. The Seat was placed in the frame, and protected on all sides. The aviator’s shoulders were flush with the surface. The Landing Gear was mainly on a large single wheel with an oleo-pneumatic spring in the center at the front and a smaller one in the same center line at the rear. When first starting the aeroplane was inclined, resting on one end of the wing, on each end of which, a wheel was placed.
Weight, Speed, Loading and Aspect Ratio
The total weight was from 900 to 970 pounds. The speed was 39 miles per hour; 27 pounds were lifted per horse-power, and 4.4 pounds carried per square foot of surface. The aspect ratio was 5.75 to 1.