Sideslips

The aim of teaching sideslips is to understand how to use the controls to balance banking forces in one direction using ailerons against banking forces produce by yaw in the opposite direction. Sideslips are used for two reasons. The first is to counteract drift and the second is to increase the drag of the aircraft and thus increase the rate of descent. The key to teaching the sideslip is to realize that this is just another manoeuvre and not to confuse teaching the basic mechanics of it with its applications to counteract drift or to increase drag. There are two primary methods to roll the aircraft, both involving increasing the angle of attack of one wing over the other. The first is to bank the aircraft by moving the ailerons. The second is to yaw the aircraft causing one wing to lead the other into the relative wind. Usually the aileron method is much more effective at producing roll than the yaw technique. The sideslip can be viewed as simply balancing these two methods of creating roll. The effect is that there is an increase in the drag because the fuselage is angled into the relative wind as a result of the yaw. Talk the students through the effects of controls, first banking the aircraft by using the normal co-ordinated turn, and then reviewing the secondary effect of the rudder, which leads to banking as well. The sideslip can then be shown to be a balance in opposite directions of these two methods of banking the aircraft. Have the student start a turn in one direction, and then apply opposite rudder to stop the turning motion as seen on the horizon. Ask them to maintain, as best they can, the same pitch attitude of the original turn. Once this manoeuvre has been practised in both directions, have the student try simultaneous input of the controls to achieve the slip without a turn. The use of sideslip to counteract drift results from more or less use of one of the means to roll the aircraft, such that the aircraft slides in the chosen direction.  The outline for this exercise is:

1. Instructor checks the student’s knowledge of the pre-takeoff check, and the 300 feet call out.
2. Instructor coaches student in the aerotow. Taking over as required to maintain good position.
3. Instructor checks student lookout, release, trimming, and locating the airfield.
4. Instructor requires good lookout before turns.
5. Student coached to demonstrate the secondary effect of the rudder that rolls the aircraft. All references are made to the horizon.
6. Student coached to do a shallow turn (20-degree). Student then asked to apply rudder opposite to the direction of the turn to stop the swinging across the horizon. The result should be a moderate sideslip.
7. Student performs sideslips with entries from shallow turns in both directions. Students who exhibit good skill may then try entering the sideslip with simultaneous use of banking the aircraft in one direction using the ailerons, and balancing out this bank with application of rudder opposite to the direction of the turn.
8. Instructor directs flight path towards the circuit.
9. Instructor checks the student’s knowledge of the downwind checks.
10. Instructor checks the student’s performance of the lookout when established on the base leg.
11. Instructor coaches the student through the flare and landing.