The Standard J-R was a development of the preliminary training tractor machine built by the same makers. It was equipped with a 175-h.p. six-cylinder Hall-Scott motor, is capable of climbing 5000 feet in 10 minutes, and had a maximum flying speed of 95 m.p.h. and a landing speed of 48 m.p.h.
Specifications from “Practical Aviation,” by Charles Hayward, 1919
Planes
The wing span on the upper plane is 42 feet 10 inches and that of the lower plane is 31 feet, the chord of both being 6 feet. The planes are set at an angle of incidence of 2 ½ degrees, have a dihedral of 3 degrees, and are swept back at the ends 5 degrees. The upper plane is staggered 12 inches forward of the \ ver and the gliding angle is 1 to 11. The U.S.A. No. 6 camber has been substituted for the R.A.F. No. 3 curve used on former machines. Including the ailerons, the total supporting surface is 417 square feet, of which the upper wings represent 258 square feet, the lower 159 square feet, and the ailerons 21 square feet each. Taking the gross weight of the machine with load as 2400 pounds, this gives a maximum loading per square foot of supporting surface of 5.75 pounds.
Each of the upper main wing sections is 20 feet 3 inches long and each of the lower sections, 14 feet 2 inches long. The wing panel over the fuselage measures inches in width, a space of 1 ½ inches being left between this panel and the wing sections and also between the fuselage and the lower wing sections. The wing struts are provided with ball-and-socket cuds and fittings to give them an even bearing at any angle of the struts.
Tail Unit
From tip to tip, the elevators measure 11 feet 3 inches across and are 2 feet 6 inches wide, ha an area of 11 square feet each. The rudder is 2 feet 8 inches wide and 4 feet 10 inches high, and therefore has an area of 10 square feet. The triangular vertical fin has an area of 3 feet 7 inches and reaches a height of 2 feet 9 inches above the horizontal stabilizer, or tail plane, which measures 10 feet in width along its trailing edge and has a depth of 3 feet 1 inch, represent; area of 23.7 feet. The system of bracing wires as well as the control cables run to the rudder and elevators.
Fuselage
The upper longerons are horizontal to the lin flight while the lower are bent in a continuous curve from the nose of the machine to the tail. The fuselage is 23 feet 6 inches long, while the over-all length of the machine is 27 feet 2 inches. At the point of attachment of the planes, the maximum width is 30 inches, while the maximum depth over the cowling at the forward, or observer’s, cockpit is 3 feet 4 inches. Metal cowling houses the motor and forms the curved top of the body ss far back as the rear end of the pilot’s seat. From the latter point, the top consists of light strips of spruce mortised into formers carried on the upper longerons and covered with fabric.
Power Plant
The engine is a Hall-Scott six-cylinder vertical water-cooled type measuring 5 ¼ by 7 inches and developing 175 h.p. at 1400 r.p.m. The motor complete weighs 605 pounds, or 4.02 pounds per horsepower. At full speed the fuel-tank capacity provides for a flight of about four and one-quarter hours, as the gasoline consumption is 14 gallons per hour and the total fuel carried is 58 ¾ gallons, 51 gallons in the main fuel tank and the balance in an auxiliary tank. Four gallons of lubricating oil are carried in the crankcase. The auxiliary tank is employ obtain a gravity feed to the carbureter as the main supply is carried in the fuselage at too low a point to permit such a feed. A fan-driven gear pump utilizes the driving force of the air against it to raise the gasoline from the main to the gravity tank.
Direct drive from engine to propeller is employed. The propeller is of black walnut, 8 feet 4 inches diameter by 5 feet 6 inches pitch, and its direction of rotation is clockwise. With its full complement of pilot, observer, fuel, oil, and instruments, the maximum loading is 13.7 pounds per horsepower.
Landing Gear
With the exception of the pneumatic t landing gear is constructed entirely of steel, the tread being 5 feet x inches and the tubular steel axles carrying two 26- by 4- inch wheels. This axle is carried in yokes, streamlined with sheet aluminum and under the stress of landing is designed to rise verft vertically in guides.
Standard JR-2
Specifications from “Practical Aviation,” by Charles Hayward, 1919
The Standard JR-2 is a more powerful type of machine equipped with a 210-h.p. motor and capable of flying at x m.p.h. The construction is very similar to that of the machine just described except that both planes are of the same span, the ailerons are fitted on ) both upper and lower planes, the propeller hub is streamlined, and three-wheel landing gear is employed.