content_image/563074.jpg
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. 

## Turn Coordination 

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. 

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 

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. 

## Slips 

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. 

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. 

<img src='content_image/563074.jpg'>

