autorotation. The first successful example of this type of aircraft was the British Fairy Rotodyne, certificated to the Transport Category in 1958. During the 1960s and 1970s, the popularity of gyroplanes increased with the certification of the McCulloch J-2 and Umbaugh. The latter becoming the Air & Space 18A. There are several aircraft under development using the free spinning rotor to achieve rotary wing takeoff per- formance and fixed wing cruise speeds. The gyroplane offers inherent safety, simplicity of operation, and out- standing short field point-to-point capability. Because the free spinning rotor does not require an antitorque device, a single rotor is the predominate configuration. Counter-rotating blades do not offer any particular advantage. The rotor system used in a gyroplane may have any number of blades, but the most popular are the two and three blade systems. Propulsion for gyroplanes may be either tractor or pusher, meaning the engine may be mounted on the front and pull the aircraft, or in the rear, pushing it through the air. The powerplant itself may be either reciprocating or turbine. Early gyroplanes were often a derivative of tractor configured airplanes with the rotor either replacing the wing or acting in conjunction with it. However, the pusher configura- tion is generally more maneuverable due to the placement of the rudder in the propeller slipstream, and also has the advantage of better visibility for the pilot. [Figure 15-1]  January 9th, 1923, marked the first officially observed flight of an autogyro. The aircraft, designed by Juan de la Cierva, introduced rotor technology that made for- ward flight in a rotorcraft possible. Until that time, rotary-wing aircraft designers were stymied by the problem of a rolling moment that was encountered when the aircraft began to move forward. This rolling moment was the product of airflow over the rotor disc, causing an increase in lift of the advancing blade and decrease in lift of the retreating blade. Cierva’s success- ful design, the C.4, introduced the articulated rotor, on which the blades were hinged and allowed to flap. This solution allowed the advancing blade to move upward, decreasing angle of attack and lift, while the retreating blade would swing downward, increasing angle of attack and lift. The result was balanced lift across the rotor disc regardless of airflow. This breakthrough was instrumental in the success of the modern helicopter, which was developed over 15 years later. (For more information on dissymmetry of lift, refer to Chapter 3— Aerodynamics of Flight.) On April 2, 1931, the Pitcairn PCA-2 autogyro was granted Type Certificate No. 410 and became the first rotary wing aircraft to be certified in the United States. The term describe this type of aircraft until the FAA later desig- nated them “gyroplanes.” 15-1 Figure 15-1. The gyroplane may have wings, be either tractor or pusher configured, and could be turbine or propeller powered. Pictured are the Pitcairn PCA-2 Autogyro (left) and the Air & Space 18A gyroplane. TYPES OF GYROPLANES By definition, the gyroplane is an aircraft that achieves lift by a free spinning rotor. Several aircraft have used the free spinning rotor to attain performance not avail- able in the pure helicopter. The rotorcraft that is capable of hovering and yet cruises in