2.12. Coordinated and Uncoordinated Flight.

p. 44

2.12.1. In a coordinated level turn (Figure 2.8) with constant bank and airspeed, the flight path of the aircraft is a true circle (no wind). Variation in the circular flight path is also caused by uncoordinated control (improperly trimmed rudder), erratic bank, or airspeed changes.

p. 44

2.12.2. A skid is caused by insufficient bank angle in relation to the turn rate of the aircraft. Excessive bottom rudder (rudder deflection to the inside of the turn) during the turn causes a skid. A skid also occurs in level flight if the nose of the aircraft rotates sideways about the vertical axis when the wings are held level due to improper rudder input. The result is a slow turn caused by the rudder only. The turn and slip ball shows a slip by displacing to the outside of the turn. Skids are dangerous due to the possibility of inadvertent roll at slow airspeeds. The impending stall is known as a “skidded turn stall”.

p. 44

2.12.3. A slip is caused by too much bank angle in relation to the aircraft turn rate. When in a turn, insufficient bottom rudder pressure in relation to the aileron pressure results in a slip. A slip can be induced by holding opposite rudder in a turn (i.e., “wing down, rudder up”). Indication of a slip is when the slip indicator ball displaces to the inside of the turn. Slips are used to align the aircraft with the runway for landing during crosswind conditions. Slips are also useful for depleting excessive energy by increasing descent rates while maintaining airspeed.

p. 44