Take-off Run, Acceleration, Lift-off

Chapter 12.4

Objectives

To know the Slipstream effect and how to compensate for it

To know the different phases of the take-off

Release Brakes, Power Up for Take-off Roll

STATIC TAKE-OFF

For a static take-off the airplane is stopped at the line-up and hold with the foot brakes. Then the take-off power is set. Still in the stopped position the minimum required take-off power is checked. Only then the brakes are released.

Release Brakes, Power Up for Take-off Roll

ROLLING TAKE-OFF

Also during a rolling take-off the airplane may be stopped in the line-up position. The brakes are then released and the take-off power is set. While the airplane is accelerating, verify that the engine is reaching its minimum required take-off power.

Release Brakes, Power Up for Take-off Roll

ROLLING TAKE-OFF

If the airplane manufacturer does not prescribe a take-off procedure, the rolling take-off may be applied. For airplanes with a fixed-pitch propeller this might eventually be more efficient. However you have to consider that with this procedure you can check the take-off power only when the airplane is already rolling. For pilots with little experience this makes it more difficult to keep the airplane on the runway centerline.

Release Brakes, Power Up for Take-off Roll

ROLLING TAKE-OFF

In order that the brakes are not activated unintentionally during the TAKE OFF RUN, the heels are consciously placed on the floor of the cabin at the beginning of the departure procedure.

Acceleration Checks

Proper Engine power setting must be checked during the acceleration phase.

This control also includes checking the AIR SPEED RISE on the ASI.

Acceleration Checks

Basically, an aircraft is controlled by controlling the attitude with one hand on the control stick while the other hand operates the power lever. This control is called HOTAS (Hands On Throttle And Stick).

An exception is the take-off with an aircraft with a control yoke. Here the following applies:

Ground roll until rotation: One hand on the throttle

Rotation: Both hands on the yoke (this usually pulls the yoke back more horizontally and avoids unwanted aileron deflections).

Initial climb: After rotation the hand can go back to the throttle. Only after climbing through 300ft AAL you can use one hand for switches, other levers, etc..

Maintaining the Direction of the Take-off Roll

At low speed, the controls have very little effect. The SLIP STREAM EFFECT acts on the fuselage and the vertical stabilizer, causing a tendency to deviate, depending on the power of the engine

This is why, at the start of the take-off roll, the rudder must be held steady by the feet on the rudder pedals which are connected to the nose wheel or with the use of brakes.

This Should Not Happen

• the aircraft to leave the RUNWAY CENTERLINE and moves towards the edge of the runway.

• False Reaction: In order for the aircraft not to come into contact with the edge of the runway or with the runway markings, the pilot will try to pull the airplane off the ground.

• The pilot then attempts to return to the runway centerline using the aileron control.
  The airplane rotates around the roll axis, increasing the danger that the tip of the wing touches the ground.

Directional stability during rotation and subsequent climb

Setting take-off power

Lot of rudder input required

Acceleration phase

The amount of rudder input decrease

Rotation

The amount of rudder input required increases again

Acceleration, Rotation, Lift-off, Climb Attitude