Resting on its undercarriage of 4 equally-spaced wheels, the Pfitzner monoplane might be compared to a flying grocery cart, with very long, rectangular wings.
In the early part of January, 1910, the monoplane designed by Mr. A. L. Pfitzner and built at the Curtiss aeroplane factory at Hammondsport, N. Y., was completed and flown. The first flights were short, due largely to the inexperience of the aviator, Mr. Pfitzner, but the monoplane was considered very promising. This aeroplane was a distinct departure from all other monoplanes in the placing of the motor, aviator, and rudders, and in an unorthodox method of transverse control by sliding surfaces, applied here for the first time.
Top Speed: 42 m.p.h.
Engine: 25 horse-power Curtiss 4-cylinder
Wingspan: 31 feet
Weight: 560 pounds
Specifications from “Monoplanes and Biplanes,” by Grover Loening, 1911
The Frame
The framework is largely a combination of numerous king-post trusses with spruce compression members and wire tension members. The framework is open throughout, thus enabling quick inspection and easy repairs. The chassis at the center is mainly of steel tubing.
The Main Wing
The main supporting plane at a 5-deg. dihedral angle consists of two main beams across which are placed spruce ribs. The surface is made of Baldwin vulcanized silk, of jet black color, tacked to the top of the ribs and laced to the frame. The curvature of the surface is slight and is designed for high speed. The spread is 31 feet, the depth 6 feet, and the surface area 186 square feet.
The Direction Rudder
The direction rudder, a rectangular surface, is placed at the front and has an area of K square feet. It is operated by wires leading to the bracket underneath the controlling column. By turning this column to either side the aeroplane turns to that side.
The Elevators
The elevation rudder consists of a single surface 17 square feet in area placed also at the front. It is operated by wires leading to the lever at the side of the controlling column. By moving this column forward or backward, the elevation rudder is caused to turn down or turn up respectively.
Roll Control
The framework of the main surface is carried out 30 inches on either end of the surface, and afford.- a place for the rail upon which the auxiliary sliding surfaces move. These sliding surfaces, or ”equalizers” are each 12 1/2 square feet in area, and when normal project 15 inches beyond the end of the surface on either side. They arc connected by a wire to each other, and a long cable running to each end through a pulley connects them to the steering wheel. The control is then as follows: If the right end of the aeroplane’ is tipped down, the wheel supported on the controlling column is turned away from the lowered side. This causes the equalizer on the raised end to be pulled in under the main surface, while at the same time the one on the other end is pulled out. This action merely decreases the supporting surface on the raised end and increases that on the lowered end, thus righting the machine. Keels. - A horizontal surface placed at the rear acts as a longitudinal stabilizer. It is 10.5 square feet in area, and is fixed firmly to the supporting framework, 10 feet in the rear of the main surface.
Propulsion. - A 25 horse-power Curtiss 4-cylinder motor is placed on the framework above the plane and at the rear of it. The motor drives direct a 2-bladed wooden propeller 6 feet in diameter and 4.5 feet pitch at 1,200 r.p.m. The propeller is of original design and said to be very efficient. The Seat for the aviator is placed out in front of the main plane and directly on the center line. The Landing Gear is on four small rubber-tired wheels, placed at the lower ends of the four main vertical posts of the chassis. The wheels are not mounted on springs. They are spaced by steel tubing and are fitted with brakes.
Weight, Speed, Loading and Aspect Ratio. - The total weight in flight is from 560 to 600 pounds. The speed is estimated at 42 miles per hour; 24 pounds are lifted per horse-power, and 3.2 pounds carried per square foot of surface. The aspect ratio is 5.17 to 1.