Forward slip question

I understand the concept of the forward slip, it just counters what I was told in 2004. I thought if you cross control your ailerons and rudder you would flip your aircraft and land on your head? This maneuver has been done many times obviously and has been for a long time but isnt it still really risky to do?

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Hey! This is a good question, thanks for asking.

Forward slips are a common occurrence in aviation. Many pilots of all skill levels use them in powered aircraft, and we use them in gliders.

You’re correct that a forward slip involves crossing the controls (this means uncoordinated flight - right aileron input with left rudder or vice versa). In a normal, coordinated turn, the ailerons and rudder are used together. A right turn will involve right aileron input and right rudder. As the left wing generates more lift, it will also generate more drag because drag is a byproduct of lift, and without rudder input the plane will yaw to the left. This is called adverse yaw. Therefore, a roll to the right, into a right turn, requires a little bit of right rudder to keep the plane pointed into the air moving past it (relative wind is the technical term).

Continuing the example from above, do you roll over and land on your head in a normal turn? Hopefully not. Think about the control inputs though: Do you hold full right aileron through your entire turn? Or do you apply right aileron until you reach a desired angle of bank, hold that angle with small aileron inputs that are near zero, and then roll back? Hopefully it’s the second option. If you did hold in full right aileron you would end up on your head!

It’s the same with a forward slip, except your controls are crossed. A slip might involve a combination of right aileron and left rudder initially (rolling to the right and swinging to the left, resulting in an ideally straight flightpath with more drag), followed by smaller adjustments to maintain the slip.

The ASK-21 (a type of glider) can be a tough aircraft to slip. In my experience, it requires quite the stomp on the rudder pedal followed by the opposite aileron movement and it’s adverse yaw to get into its “sweet spot” and slip properly. After that, it’s a dance on the rudder pedals to maintain it. If your nose is pointed left, you can (and usually will, if you’re in a pattern) make right turns, and vice versa!

So to answer your question…

…nothing to worry about as long as you have the altitude and airspeed!

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I watch almost every Navy and Air Force Pilots do this every day to stabilize their approach during crosswind landing.
I use it every time I fly my glider as well to avoid sideloading the landing gear

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Thank you for the information this helps a lot.

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