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| CHAPTER 7. Takeoff and Departure Climbs
Takeoff Roll After taxiing onto the runway, the WSC aircraft should be carefully aligned with the intended takeoff direction and the nosewheel positioned straight down the runway on the centerline. After releasing the brakes, the throttle should be advanced smoothly and continuously to takeoff power. [Figure 7-2] This can be done with the foot or the hand cruise throttle.
The advantage of using the foot throttle is that the takeoff can be aborted quickly if required. The disadvantage is that the foot can slip off or be knocked off during the critical takeoff phase of fl ight. The advantage of using the hand cruise throttle during takeoff is having a solid and set throttle that the pilot does not have to worry about holding during the takeoff phase of fl ight. Students have been known to release the foot throttle on takeoff, resulting in catastrophic consequences during the lift-off and initial climb phases of fl ight. Students may be encouraged to use the hand throttle by the instructor or the instructor must be able to immediately apply the hand or secondary foot throttle if a student lets up on the throttle during this critical takeoff and climb phase. An abrupt application of power may cause the aircraft to yaw sharply to the left (or right depending on the propeller rotation) because of the torque effects of the engine and propeller. This is most apparent in high horsepower engines. As the aircraft starts to roll forward, the pilot should ensure that both feet are on the front steering fork and not applying the brake. As speed is gained, the control bar fore and aft pitch tends to assume a neutral trim position. The wing should be maintained level side to side with the control bar. At the same time, directional control should be maintained with smooth, prompt, positive nosewheel steering throughout the takeoff roll. The effects of engine torque at the initial speeds tend to pull the nose to the left (or right depending on the propeller rotation). The pilot must steer the WSC aircraft straight down the middle of the runway with the feet. The positioning of the wing has no effect of steering on the ground. The common saying among WSC pilots is “you steer with your feet, you fl y with your hands.” While the speed of the takeoff roll increases, increasingly more pressure is felt on the control bar to the ground roll trim position. Letting the wing pitch pressures determine the fore and aft control bar position provides the least drag for the WSC aircraft to accelerate. The pilot maintains directional control down the center of the runway with the foot steering, keeps the wings level side to side, and allows the wing to determine the pitch angle during the acceleration. Lift-Off Since a good takeoff depends on the proper takeoff attitude, it is important to know how this attitude appears and how it is attained. The ideal takeoff attitude requires only minimum pitch adjustments shortly after the airplane lifts off to attain the speed for the best rate of climb (VY). [Figure 7-3] The pitch attitude necessary for the aircraft to accelerate to VY speed should be demonstrated by the instructor and memorized by the student. Initially, the student pilot may have a tendency to hold excessive control bar forward/nose up pressure just after lift-off, resulting in an abrupt pitch-up. The fl ight instructor should be prepared for this. For a normal takeoff, the WSC aircraft should lift off the ground gradually and smoothly.
Each type of WSC aircraft has a best pitch attitude for normal lift-off; however, varying conditions may make a difference in the required takeoff technique. A rough fi eld, a smooth fi eld, a hard surface runway, or a short or soft, muddy fi eld, calls for a slightly different technique as does smooth air in contrast to a strong, gusty wind. The different techniques for those other-than-normal conditions are discussed later in this chapter. As the WSC aircraft accelerates and obtains the speed it needs to lift off, a slight push forward on the control bar provides the initial attitude to lift-off. This is often referred to as “rotating.” At this point, the climb speed should be immediately established for the particular condition. For calm winds, this would be the trim position or the manufacturer recommended takeoff safety airspeed. The wings must be kept level by applying side to side pressure as necessary. Since some forward pressure was required to rotate, this pressure must be relaxed smoothly so that takeoff attitude is not too high. This requires the control bar being brought back to trim and applying some nose down pressure to avoid popping off as the WSC aircraft leaves the ground. Each make and model is different and the high power WSC aircraft must provide more nose down pressure after rotation to keep the attitude low. A good takeoff is a smooth and gradual liftoff. It is important to hold the correct attitude constant after rotation and liftoff. As the aircraft leaves the ground, the pilot must continue to be concerned with maintaining the wings in a level attitude, as well as holding the proper pitch attitude. An outside visual scan to attain/maintain proper pitch and bank attitude must be intensifi ed at this critical point. During takeoffs in a strong, gusty wind, it is advisable that an extra margin of speed be obtained before the WSC aircraft is allowed to leave the ground. A takeoff at the normal takeoff speed may result in a lack of positive control, or a stall, when the WSC aircraft encounters a sudden lull in strong, gusty wind, or other turbulent air currents. In this case, the pilot should allow the aircraft to stay on the ground longer by pulling the control bar towards the chest keeping the nose down to attain more speed; then make a smooth, positive rotation to leave the ground. |
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