Secondary Effect of Rudder

In this lesson, we will demonstrate the secondary effect of the rudder.

Learning Points

We have seen already that when the rudder is used with the wings level, the glider yaws, and does not turn. What happens if we use the rudder on its own, without actively keeping the wings level?

When flying slowly, if the rudder is used on its own the glider yaws, rolls, and the nose goes down. At best you’ll be in a skidding turn, but the result could easily be a spin or spiral dive, with significant loss of height.

When flying just above the stall speed, whether intentionally or inadvertently, heavy use of the rudder will result in very little yaw and a lot of roll – or in other words, a stall with wing drop, possibly leading to a spin.

When flying more quickly and using the rudder alone, the same effect is seen, but is less marked. A look at the string shows the glider skids.

If we use the aileron and rudder together, we can make a coordinated turn, meaning there is no wing drop or skid as we turn.

Demonstration

This demonstration is not the way to fly! Your goal is always to fly ‘coordinated’, using matching aileron and rudder movements together.

Alternative Video without animation

Further Reading and References

• Gliding From Passenger to Pilot, 2nd Edition: Pages 35-37
• BGA Instructors’ Reference Cards: Ex 6
• Gliding: The British Gliding Association Student Pilot Manual, Section 4.5 and website.