NORMAL TAKEOFF TAKEOFF 20-3 Figure 20-4. Best angle-of-climb (V$_{X}$ speed is used when obstacles are a factor. V$_{Y}$ provides the most altitude gain for a given amount of time. B e s t R a t e o f C l i m b ( V Y ) B e s t A n g $_{l}$e o f C l i m b ( V X ) 30 A normal takeoff for certificated gyroplanes is accom- plished by prerotating to a rotor r.p.m. slightly above that required for flight and disengaging the rotor drive. The brakes are then released and full power is applied. Lift off will not occur until the blade pitch is increased to the normal in-flight setting and the rotor disk tilted Takeoffs are classified according to the takeoff surface, obstructions, and atmospheric conditions. Each type of takeoff assumes that certain conditions exist. When conditions dictate, a combination of takeoff techniques can be used. Two important speeds used for takeoff and initial climbout are V$_{X}$ and V$_{Y}$. V$_{X}$ is defined as the speed that provides the best angle of climb, and will yield the maximum altitude gain over a given distance. This speed is normally used when obstacles on the ground are a factor. Maintaining V$_{Y}$ speed ensures the aircraft will climb at its maximum rate, providing the most altitude gain for a given period of time.  [Figure 20-4] Prior to any takeoff or maneuver, you should ensure that the area is clear of other traffic. The normal takeoff assumes that a prepared surface of adequate length is available and that there are no high obstructions to be cleared within the takeoff path. The normal takeoff for most amateur-built gyroplanes is accomplished by prerotating to sufficient rotor r.p.m. to prevent blade flapping and tilting the rotor back with cyclic control. Using a speed of 20 to 30 m.p.h., allow the rotor to accelerate and begin producing lift. As lift increases, move the cyclic forward to decrease the pitch angle on the rotor disc. When appreciable lift is being produced, the nose of the aircraft rises, and you can feel an increase in drag. Using coordinated throttle and flight control inputs, balance the gyroplane on the main gear without the nose wheel or tail wheel in contact with the surface. At this point, smoothly increase power to full thrust and hold the nose at takeoff attitude with cyclic pressure. The gyroplane will lift off at or near the minimum power required speed for the aircraft. V$_{X}$ should be used for the initial climb, then V$_{Y}$ for the remainder of the climb phase. The prerotators on certificated gyroplanes remove the possibility of blade flap during prerotation. Before the clutch can be engaged, the pitch must be removed from the blades. The rotor is then prerotated with a 0° angle of attack on the blades, which prevents lift from being produced and precludes the possibility of flapping. When the desired rotor speed is achieved, blade pitch is increased for takeoff. minimize the length of the ground roll that is required to get the gyroplane airborne.