The 1911 version of Robert Esnault-Pelterie differed radically from the older type in the method of elevation control and in the construction of the tail as well as in propeller, motor, etc. This type was built in two sizes (one or two seater) and largely preserved the graceful lines of its predecessors. After the flights of Laurens and Bournique, with and without passenger, and because of its high speed, reliability and stability, the scarlet bird-like R. E. P. took its place among the very best flying machines of the time.
Top Speed: 60 m.p.h.
Engine: five-cylinder 55 horse-power R. E. P. rotary
Wingspan: 42 feet
Weight: 1,180 pounds
Bournique, in the small R. E. P. , flew 60 miles an hour, and not much later Laurens established a passenger speed record. Bournique on December 31st, 1910, in competition for the Michelin cup (awarded annually for the longest sustained flight), flew this type 331 miles.
Specifications from “Monoplanes and Biplanes,” by Grover Loening, 1911
The Frame
The splendid non-soldered steel-tube construction of the frame gives great strength and durability. In the minutest details the R. E. P. exhibits excellent workmanship. All joints are welded.
The Main Wing
The plane is similar in shape and structure to the old R. E. P. It is fixed to the central frame by four cables, and its incidence cannot be changed as formerly. It is, however, warpable. The two halves are set at an upward dihedral angle, and not turned down as on the old type. The material used is a red vulcanized cotton fabric. The cables used to support the frame are more numerous, and the plane is braced both above and below. The frame consists of two main steel laterals with ribs having an I-section. The spread is 42 feet, the mean chord 6 1/2 feet, and the area 270 square feet.
The Elevators
The elevation rudder consists of two flaps on the end of the horizontal tail. The alteration of the incidence of the main planes to control elevation is entirely discarded in this type. The elevators are controlled by the to-and- fro motion of the left-hand lever.
The Direction Rudder
Two small planes at the rear, moved jointly, serve as the direction rudder. They are operated either by the side-to-side motion of the right-hand lever, as on the former type, or by an ordinary foot pedal.
Roll Control
The widely used warping method of transverse control is here employed. The warping is controlled by the side-to-side motion of the left-hand lever.
Tail
The rear is greatly altered in form. The vertical empennage is very much smaller, as is also the horizontal non-lifting tail. The entire tail can readily be dismounted.
Propulsion
A five-cylinder 55 horse-power R. E. P. motor is installed at the front, and the recent success of this type is largely due to the great improvements in this motor. The two-bladed 8 1/4 foot wooden Regy propeller is driven direct at a speed varying between 500 and 1,250 r.p.m. The four-bladed propeller formerly used is discarded. The
Landing Gear
The landing gear is altogether different from the old type, and is very simple. The single central wheel is abandoned, and in its stead is a large skid fitted by a springy telescoping steel tube to the main fuselage. A steel-tube frame and axle also support two rubber-tired wheels, one on either side of this skid, fitted with rubber rope springs. A small skid is fixed at the rear. No wheels are placed on the ends of the plane. The Seat is placed as formerly, and is well protected.
Speed, Weight, Loading and Aspect Ratio
The speed is almost 60 miles an hour. The total weight is from 1,180 to 1,240 pounds; 22.5 pounds are carried per horsepower, and 4.6 per square foot of surface. The aspect ratio is 6.5 to 1.