Normal Takeoff in Weight-Shift-Control Aircraft (Part One)

Prior to Takeoff

Before taxiing onto the runway or takeoff area, the pilot should ensure that the engine is operating properly and that all controls, including trim (if equipped), are set in accordance with the before takeoff checklist. In addition, the pilot must make certain that the approach and takeoff paths are clear of other aircraft. At uncontrolled airports, pilots should announce their intentions on the common traffic advisory frequency (CTAF) assigned to that airport. When operating from an airport with an operating control tower, pilots must contact the tower operator and receive a takeoff clearance before taxiing onto the active runway.

It is not recommended to take off immediately behind another aircraft, particularly large, heavily loaded transport airplanes because of the wake turbulence that is generated. Even smaller aircraft can generate vortices that can cause the WSC aircraft to lose control during takeoff. Always wait for aircraft vortices to clear before taking off.

While taxiing onto the runway, the pilot can select ground reference points that are aligned with the runway direction as aids to maintaining directional control during the takeoff. These may be runway centerline markings, runway lighting, distant trees, towers, buildings, or mountain peaks.

Normal Takeoff

A normal takeoff is one in which the aircraft is headed into the wind, or the wind is very light. Also, the takeoff surface is firm and of sufficient length to permit the aircraft to gradually accelerate to normal lift-off and climb-out speed, and there are no obstructions along the takeoff path.

There are two reasons for making a takeoff as nearly into the wind as possible. First, the aircraft’s speed while on the ground is much lower than if the takeoff were made downwind, thus reducing wear and stress on the landing gear. Second, a shorter ground roll and, therefore, much less runway length is required to develop the minimum lift necessary for takeoff and climb. Since the aircraft depends on airspeed in order to fly, a headwind provides some of that airspeed, even with the aircraft motionless, from the wind flowing over the wings.

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.

Figure 7-2. Lined up in the middle of the runway and ready to apply full power for takeoff.

Figure 7-2. Lined up in the middle of the runway and ready to apply full power for takeoff.

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 flight. 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 flight. Students have been known to release the foot throttle on takeoff, resulting in catastrophic consequences during the lift-off and initial climb phases of flight. 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 fly 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 flight instructor should be prepared for this. For a normal takeoff, the WSC aircraft should lift off the ground gradually and smoothly.

Figure 7-3. Initial roll and takeoff attitude.

Figure 7-3. Initial roll and takeoff attitude.

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 field, a smooth field, a hard surface runway, or a short or soft, muddy field, 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 intensified 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.

Flight Literacy Recommends

Rod Machado's Private Pilot Handbook -Flight Literacy recommends Rod Machado's products because he takes what is normally dry and tedious and transforms it with his characteristic humor, helping to keep you engaged and to retain the information longer. (see all of Rod Machado's Products).