for adverse yaw and aileron drag. Adverse yaw in gliders  can be more pronounced due to the much longer wings as  compared to an airplane of equal weight. The longer wings  constitute longer lever arms for the adverse yaw forces to act  on the glider. Therefore, more rudder movement is necessary  to counteract the adverse yaw and have a coordinated turn. the radius of the turn would be four times greater. Although  the radius of turn is also dependent on a glider’s airspeed and  angle of bank, the relationship is the opposite of rate of turn.  As the glider’s airspeed is increased with the angle of bank  held constant, the radius of turn increases. On the other hand,  if the angle of bank increases and the airspeed remains the  same, the radius of turn is decreased.  [Figure 3-29]  When  flying in thermals, the radius of turn is an important factor as  it helps to gain the maximum altitude. A smaller turn radius  enables a glider to fly closer to the fastest rising core of the  thermal and gain altitude more quickly. A slip is a descent with one wing lowered and the glider’s  longitudinal axis at an angle to the flightpath. It may be used  for one or both of two purposes: to steepen the approach path  without increasing the airspeed, as would be the case if a dive  were used, or used to make the glider move sideways through  the air to counteract the drift that results from a crosswind. It is important that rudder and aileron inputs are coordinated  during a turn so maximum glider performance can be  maintained. If too little rudder is applied, or if rudder is  applied too late, the result is a slip. Too much rudder, or  rudder applied before aileron, results in a skid. Both skids  and slips swing the fuselage of the glider into the relative  wind, creating additional parasite drag, which reduces lift  and airspeed. Although this increased drag caused by a slip  can be useful during approach to landing to steepen the  approach path and counteract a crosswind, it decreases glider  performance during other phases of flight. Formerly, slips were used as a normal means of controlling  landing descents to short or obstructed fields, but they are  now primarily used in the performance of crosswind and  short-field landings. With the installation of wing flaps  and effective spoilers on modern gliders, the use of slips to  steepen or control the angle of descent is no longer the only  procedure available. However, pilots still  need skill in the  performance of forward slips to correct  for possible errors  in judgment of the landing approach. The shape of the glider’s wing planform  can greatly affect  the slip. If the glider has a rectangular wing p lanform, the slip  has little effect on the lift production of the wing other than  the wing area being obscured by the  fuselage vortices. The  direction of the relative wind to the wing has the same effect  on both wings so no inequalities of lift form. However, if the  wing is tapered or has leading edge aft swee p, then the relative  wind has a large effect on the production of lift.  When rolling into a turn, the aileron on the inside of the  turn is raised and the aileron on the outside of the turn is  lowered. The lowered aileron on the outside wing increases  lift by increasing wing camber and produces more lift for that  wing. Since induced drag is a byproduct of lift, the outside  wing also produces more drag than the inside wing. This  causes adverse yaw, a yawing tendency toward the outside  of the turn. Coordinated use of rudder and aileron corrects  30° 45° 60° TAS 40 MPH TAS 60 MPH TAS 80 MPH feet Turn radius 7 0 1 feet Turn radius 0 4 2 feet Turn radius 8 2 4 feet Turn radius 5 8 1 feet Turn radius 7 1 4 feet Turn radius 0 4 7 feet Turn radius 2 6 0 feet Turn radius 9 3 1 feet Turn radius 7 4 2 Level stall airspeed at gross weight is 38 knots Stall speed: 41 knots Stall speed: 45 knots Stall speed: 53 knots Figure 3-29.  A glider’s radius of turn as compared to angle of bank. 3-15 Slips Turn Coordination