Runway Sideslip Drill?

[whifferdill]

Honestly, for me that simply means that at that point the controls are in the neutral position and you are in coordinated flight. Now how you get them there I'm not sure what you are thinking. You don't just let go of them, you return to neutral and exit the slip with the same coordination you entered it. If it's a side slip you are going to keep the heading constant as it says in the side text.

You exit the slip you are in, and then apply slipping turn inputs in the opposite direction. THEN you neutralize the controls and continue on your way, tracking the runway. It's so easy to go up and do this stuff.

But I think you hinted that the main problem here - that the picture is misleading at best, and IMO incorrect at worst.

You're certainly entitled to your opinion on that and I disagree. I think they are good exercises for students as they clearly demonstrate the nuances of different aircraft in cross control configuration. In a Champ or Cub for instance when you move the stick to the left without moving the rudder the first thing that is going to happen is you're gonna start turning right due to the extreme adverse yaw in those designs so to prevent that and hold heading you first have to apply left rudder then as you increase aileron you gradually feed in right rudder. You do this back and forth gracefully passing through neutral while keeping the compass dead on heading with precision. It's not a yank and bank exercise so maybe it would bore you to tears but hey, just give it a try, it's not as easy as it sounds to keep that heading dead nuts on.

I understand adverse yaw. I learned to fly in a Champ. You are describing a type of "dutch roll" exercise. I like those. Done them plenty. Different from the runway drill, though.

 

[Henning]

Semantics, mostly. If you won't, then you can't, not with the caveat that controls must be neutralized and nothing else.

That's why "The Drill" fails as presented. In a no wind situation, what he is proposing is impossible. You can't just throw in a slip, scootch the plane sideways, let go of the slip, and be pointed straight down the runway, you will be pointed off to the side of the runway same as if you had made a coordinated turn.

Give a shout and we'll go grab a plane if you don't understand what we're getting at. "The Drill" is saying the slip scootches the plane sideways, we are saying it is just making an uncoordinated s turn. Not that these aren't useful to burn off speed from a hot final right over the runway, but they are not what is being presented in "The Drill".

 

[Silvaire]

... "The Drill" as described and drawn above is trying to demonstrate that the plane is being shifted laterally by the slip, when that is not what is occurring. It is just making uncoordinated S turns.

Nope Henning, you have left aileron and right rudder, your drifting off to the left of the runway, you are in a slip and your heading is not changing exactly as if you were in a forward slip only you have kept the nose on the initial heading. You could hold that all day long and continue to drift to the left and maintain the same heading.

The only difference between the two is the method of entry. For a side slip you keep the nose on it's initial heading. After that entry the control inputs are identical so how can one be a "turn" and the other not?

 

[asechrest]

Nope Henning, you have left aileron and right rudder, your drifting off to the left of the runway, you are in a slip and your heading is not changing exactly as if you were in a forward slip only you have kept the nose on the initial heading. You could hold that all day long and continue to drift to the left and maintain the same heading.

The only difference between the two is the method of entry. For a side slip you keep the nose on it's initial heading. After that entry the control inputs are identical so how can one be a "turn" and the other not?

Ok, now, as you reach the left edge of the runway, do nothing except neutralize the controls. What's your flight path over the ground now?

 

[Henning]

Where "The Drill" works nicely is in teaching crosswind control for runway placement, but it requires a crosswind to work. When "The Drill" as referenced in the OP turned it into a zero wind exercise, he eliminated the key component to it being possible to achieve the intended goal. As an energy reduction drill, I'm all for it, but it's not an accurate way to teach someone the aerodynamics of a slip, because it is incorrect. A drill that has an impossible outcome is frustrating for a student at best.

 

[Henning]

Ok, now, as you reach the left edge of the runway, do nothing except neutralize the controls. What's your flight path over the ground now?

Exactly.

 

[whifferdill]

The aircraft will actualy start moving side ways. It is also moving forward at the same time. Some people think the airplane will not actualy move side ways.

When people say the airplane "starts moving sideways", I interpret this as a flight path change - like the runway drill. To me, this is different from simply flying along the same fight path you were before you slipped, but with your nose pointing in a different direction from your flight path. I understand what's going in a slip.

 

[Silvaire]

Ok, now, as you reach the left edge of the runway, do nothing except neutralize the controls. What's your flight path over the ground now?

If you neutralize the controls you are no longer in a slip so your flight path over the ground will be where the nose is pointed. Remember the criteria for entering and exiting the constant heading side slip is to keep the heading constant. You don't just let go of the controls. As you decrease bank you also decrease your rudder offset in coordination which is the whole point of the drill to begin with.

 

[vintage cessna]

That's why "The Drill" fails as presented. In a no wind situation, what he is proposing is impossible. You can't just throw in a slip, scootch the plane sideways, let go of the slip, and be pointed straight down the runway, you will be pointed off to the side of the runway same as if you had made a coordinated turn.

Give a shout and we'll go grab a plane if you don't understand what we're getting at. "The Drill" is saying the slip scootches the plane sideways, we are saying it is just making an uncoordinated s turn. Not that these aren't useful to burn off speed from a hot final right over the runway, but they are not what is being presented in "The Drill".

Exactly. You don't believe an airplane can move sideways, just an uncoordinated turn. We have understood this from the beginning, no confusion. You are just flat out wrong.

 

[Henning]

Nope Henning, you have left aileron and right rudder, your drifting off to the left of the runway, you are in a slip and your heading is not changing exactly as if you were in a forward slip only you have kept the nose on the initial heading. You could hold that all day long and continue to drift to the left and maintain the same heading.

The only difference between the two is the method of entry. For a side slip you keep the nose on it's initial heading. After that entry the control inputs are identical so how can one be a "turn" and the other not?

The difference between a forward slip and a side slip is there is a crosswind component that is considered in one. There is no operational difference between the two, only an objective difference. Just do as described, zero wind, slip the plane to the right, let go of the controls to return to coordinated level flight. What direction are you now pointing? If you move to the side, your inertial vector will change to that direction regardless of where the nose is pointed at any given moment. Basic Newtonian physics.

 

[whifferdill]

That's why "The Drill" fails as presented. In a no wind situation, what he is proposing is impossible. You can't just throw in a slip, scootch the plane sideways, let go of the slip, and be pointed straight down the runway, you will be pointed off to the side of the runway same as if you had made a coordinated turn.

Give a shout and we'll go grab a plane if you don't understand what we're getting at. "The Drill" is saying the slip scootches the plane sideways, we are saying it is just making an uncoordinated s turn. Not that these aren't useful to burn off speed from a hot final right over the runway, but they are not what is being presented in "The Drill".

Truth.

 

[vintage cessna]

When people say the airplane "starts moving sideways", I interpret this as a flight path change - like the runway drill. To me, this is different from simply flying along the same fight path you were before you slipped, but with your nose pointing in a different direction from your flight path. I understand what's going in a slip.

A side slip IS a flight path change. You won't see a change over the ground if you are slipping into a crosswind at just the right amount to compensate for drift.

 

[Lindberg]

Lots of people crab down final once they get past the student pilot stage, and branch out from "what I was taught". There is no turning involved.

You've said that slipping does involve turning, and now you say that crabbing doesn't involve turning. Unless you and I are applying different definitions of "turn," it's beginning to sound like you are trolling.

Here's what Langewiesche said about using slips for crosswind landings:

If you understand wind drift, as explained earlier in this book, you can see that there is only one way of having straight, head-on motion over the ground while flying in a cross wind: the airplane must slice sideways through the air. If the cross wind is from the left, the airplane will tend to move, relative to the ground, sliding toward the right; and the only way to make it go straight relative to the ground is to make it slice leftward through the air.

There are maneuvers that will do this. One method is to dip the left wing slightly down by aileron, at the same time keeping it from making a left turn by putting on some right rudder. This results in a sideslip toward the left. If done to the correct degree, this leftward motion of the airplane through the air will just cancel its rightward motion with the air and the net result will be straight forward motion relative to the ground.

He seems to think that a sideslip causes the airplane to move laterally without turning.

The sideslip drill that you seem to have an issue with is simply an exercise to demonstrate and practice the coordinated cross-controlling necessary to get into and out of the slip while holding heading. Nothing more or less. If you think you can't do it, that's one thing. But saying it's impossible, when other posters have repeatedly told you they've done it, and suggesting they aren't actually pilots, is insulting.

 

[Henning]

Don't give up yet! I've got a video to post!

Dude, did you export it to ILM for some "magic"?

 

[Silvaire]

...let go of the controls to return to coordinated level flight...

I am at a loss as to what part of "maintain a constant heading" you don't understand. At no point in the drill are you instructed to "let go of the controls" You have two feet and two rudder pedals, you can do this.

 

[vintage cessna]

The difference between a forward slip and a side slip is there is a crosswind component that is considered in one. There is no operational difference between the two, only an objective difference. Just do as described, zero wind, slip the plane to the right, let go of the controls to return to coordinated level flight. What direction are you now pointing? If you move to the side, your inertial vector will change to that direction regardless of where the nose is pointed at any given moment. Basic Newtonian physics.

You are now pointing parralell to the centerline. Plane will continue to displace to the right ( Mr Newton, inertia) . Once intertia is overcomed , plane will track parallel to centerline ( no wind situation) .

 

[whifferdill]

A side slip IS a flight path change. You won't see a change over the ground if you are slipping into a crosswind at just the right amount to compensate for drift.

You can't be serious. Can you describe the flight path change that is occurring here? There was no wind.

You've said that slipping does involve turning, and now you say that crabbing doesn't involve turning. Unless you and I are applying different definitions of "turn," it's beginning to sound like you are trolling.

Your statements have me wondering if you are a pilot. I've said (and shown in video) that a slip can be balanced such that there is no turning, or imbalanced such that a slipping turn happens. Regarding crabbing, I only know of one definition unless you're a fisherman - that is flying in coordinated flight, along a constant flight path that causes the airplane's path over the ground to match the runway track when the wind is blowing. There is no turning. I'm not sure which thread you've been reading.

 

[vintage cessna]

STOP THE PRESSES! Did his hero , the author of Stick and Rudder use the term SIDESLIP?

 

[Silvaire]

Think of this scenario:

Short final with 15 kt crosswind from the left, you are in a side slip with nose aligned perfectly with the runway and no drift.

The crosswind suddenly drops to zero.

If you make no control adjustments what is going to happen to your ground track?

 

[vintage cessna]

You can't be serious. Can you describe the flight path change that is occurring here? There was no wind.

Your statements have me wondering if you are a pilot. I've said (and shown in video) that a slip can be balanced such that there is no turning, or imbalanced such that a slipping turn happens. Regarding crabbing, I only know of one definition unless you're a fisherman - that is flying in coordinated flight, along a constant flight path that causes the airplane's path over the ground to match the runway track when the wind is blowing. There is no turning. I'm not sure which thread you've been reading.

Did you read post 133. See what your hero said, about " slicing" through the air, used the term SIDESLIP, didn't just say slip.

 

[whifferdill]

STOP THE PRESSES! Did his hero , the author of Stick and Rudder use the term SIDESLIP?

You win. Now...does "side" mean the airplane adopts a new flight path, or just flies with the nose yawed to the side.

 

[FastEddieB]

Dude, did you export it to ILM for some "magic"?

Not yet.

Back home and importing it into iMovie as we speak.

 

[whifferdill]

Think of this scenario:

Short final with 15 kt crosswind from the left, you are in a side slip with nose aligned perfectly with the runway and no drift.

The crosswind suddenly drops to zero.

If you make no control adjustments what is going to happen to your ground track?

You will move to the left of the runway of course, but it's not because you were in a slip. It's because of your flight path. Take the same x-wind and crab down final instead of slipping. Take the x-wind away and you will move to the left just the same as if you were slipping. It's a flight path issue, not a slip issue.

 

[Henning]

A side slip IS a flight path change. You won't see a change over the ground if you are slipping into a crosswind at just the right amount to compensate for drift.

Exactly, when you have a cross wind, you are now creating a horizontal component of lift, to balance against a horizontal component of wind. Now if you trace our path through the column of air, you will see that it represents an arc, we are flying a big, huge, arc through a moving fluid. This is easy in the air and we deal with it setting up a Crab Angle. The trick always comes at the interface tradition from air to land because you have three bodies of energy to manage, the energy of the plane you are in, and the energy of the fluid you are in, and the energy of the surface. You have to offset some plane energy into the fluid energy to balance your trajectory against the surface. We do this through the bank angle, and then to ease the translation to the surface, we add in the rudder required to align us with our tragectory, as we use increasing bank angle to counter the fluid energy as we slow down in the fluid supporting our wings and transition our weight on the wheels.

It's all just managing energies to balance each other out. But when you take the crosswind out of the drill, you have created an impossibility as described. Notice, there is only one reference been found to "The Drill".

 

[whifferdill]

Did you read post 133. See what your hero said, about " slicing" through the air, used the term SIDESLIP, didn't just say slip.

I don't know why you're hung up on the name. Since the forward and side slip are identical aerodynamically, does the "forward" slip also cause this same "sideways" movement, or does is slice "forward" though the air. This tangent you're on is just silly.

What's not silly is that you said a slip is a flight path change. That is a serious problem.

 

[Silvaire]

You will move to the left of the runway of course, but it's not because you were in a slip. It's because of your flight path. Take the same x-wind and crab down final instead of slipping. Take the x-wind away and you will move to the left just the same as if you were slipping. It's a flight path issue, not a slip issue.

Come on wiff get with it here. You are on that flight path with the nose pointed down the runway because you are in a slip. If you weren't in a slip you wouldn't be on that flight path with the nose pointed down the runway, you'd be drifting off to the right.

Now same scenario, crosswind has suddenly died and you're drifting left. What happens when you "let go" of the controls?

 

[vintage cessna]

You win. Now...does "side" mean the airplane adopts a new flight path, or just flies with the nose yawed to the side.

Read the excerpt from post 133 again. Lang... whatever his name, describes it as a leftward motion through the air, that would counter the rightward motion caused by drift from a crosswind. That means he and I think it is a definite change in flight path. The nose shouldn't yaw to the side if the right amount of control input is used in a side slip. Forward slip, the nose will yaw to the side. Forward slip you want as much yaw as possible so that as much of the fuselage as you can get into the relative wind for drag. Side slip, you want no yaw.

 

[vintage cessna]

Exactly, when you have a cross wind, you are now creating a horizontal component of lift, to balance against a horizontal component of wind. Now if you trace our path through the column of air, you will see that it represents an arc, we are flying a big, huge, arc through a moving fluid. This is easy in the air and we deal with it setting up a Crab Angle. The trick always comes at the interface tradition from air to land because you have three bodies of energy to manage, the energy of the plane you are in, and the energy of the fluid you are in, and the energy of the surface. You have to offset some plane energy into the fluid energy to balance your trajectory against the surface. We do this through the bank angle, and then to ease the translation to the surface, we add in the rudder required to align us with our tragectory, as we use increasing bank angle to counter the fluid energy as we slow down in the fluid supporting our wings and transition our weight on the wheels.

It's all just managing energies to balance each other out. But when you take the crosswind out of the drill, you have created an impossibility as described. Notice, there is only one reference been found to "The Drill".

If you are in a proper side slip i.e., constant heading, you are not flying an arc, you are flying a straight diagonal line, just like any flying textbook will depict. If you were on an arc, in a no wind situation you could put the airplane is a side slip and move about in a circle without ever changing your heading.

 

[whifferdill]

Come on wiff get with it here. You are on that flight path with the nose pointed down the runway because you are in a slip. If you weren't in a slip you wouldn't be on that flight path with the nose pointed down the runway, you'd be drifting off to the right.

Jeez, now you are equating flight path with the direction the nose is pointing. So you think that if you're slipping down final in a left x-wind, aligned and tracking the runway, that the airplane will drift to the right if you simply neutralize the slip? If you believe this, you need to shut down the computer, go find an airplane and a x-wind, and go do some flying.

Three Amigos, post 74. Please fly and post your results. The discussion will be a lot more interesting and relevant if some of you get off the keyboard and actually go do some flying like I've been doing. Until then, we are just continuing down a path of epic futility. Later.

 

[Henning]

To move the plane to the side of the runway, you have changed the inertia of the whole plane to that vector. When you release the slip the plane will be pointed on that vector.

If anyone in SoFla wants a demo, hit me up.

 

[vintage cessna]

Jeez, now you are equating flight path with the direction the nose is pointing. So you think that if you're slipping down final in a left x-wind, aligned and tracking the runway, that the airplane will drift to the right if you simply neutralize the slip? If you believe this, you need to shut down the computer, go find an airplane and a x-wind, and go do some flying.

Three Amigos, post 74. Please fly and post your results. The discussion will be a lot more interesting and relevant if some of you get off the keyboard and actually go do some flying like I've been doing. Until then, we are just continuing down a path of epic futility. Later.

Go back and read Stick and Rudder again. I have done side slips many times and don't get the motions you speak of. You keep saying all slips are the same. The FAA, every text book I've seen, and the author of stick and rudder distinguish between the different types of slips. Your video is not proof of the type of slip that Langw. calls a side slip. Your nose is yawing back and forth so you are doing a forward slip. I bet Lang. talks about forward slips also. You have been telling everyone they are not smart enough to understand what you are saying. We knew what you were saying, but you have a mental block to the truth.

 

[Silvaire]

Jeez, now you are equating flight path with the direction the nose is pointing. So you think that if you're slipping down final in a left x-wind, aligned and tracking the runway, that the airplane will drift to the right if you simply neutralize the slip? If you believe this, you need to shut down the computer, go find an airplane and a x-wind, and go do some flying...

You need to slow down and read

I said that if you had the crosswind and the nose was pointed down the runway and you were not in a slip your flight path would be drifting to the right.

Are you disputing that?

I'll agree that there is a lot of confusion concerning forward and side slips to the point that some people don't bother to acknowledge a difference. Here is how I have always understood it based on all of the official text and diagrams that are out there, and I'm going to make this statement assuming zero wind for simplicity's sake.

In a Forward slip you maintain your ground track while displacing the nose to the left or right and altering your heading.

In a side slip you maintain your heading while altering your ground track left or right.

Now if you're landing in a crosswind you might not think you are altering your ground track because you are tracking straight down the runway but actually you are because without the slip you would not be on that ground track with the nose aligned with the runway.

It's as simple as that for me, I really don't understand the hoopla

 

[vintage cessna]

To move the plane to the side of the runway, you have changed the inertia of the whole plane to that vector. When you release the slip the plane will be pointed on that vector.

If anyone in SoFla wants a demo, hit me up.

When you say " pointed" do you mean heading? As in you start the left side slip on a heading of 360, after releasing the side slip you would be on a heading of something left of 360, like say 350?

 

[Silvaire]

In any slip whether forward or side the nose is displaced from the relative wind. If you simply "let go" of the controls the nose will point into the wind. To properly end the side slip you return the controls to neutral while maintaining the heading constant. You don't "let go" of anything.

This ain't rocket science here.

 

[Henning]

When you say " pointed" do you mean heading? As in you start the left side slip on a heading of 360, after releasing the side slip you would be on a heading of something left of 360, like say 350?

Come down final runway 09 in zero wind conditions lined up centerline. Over the threshold I throw in a left slip and move it across the runway at an angle as demonstrated above of 15°. When I neutralize aileron and rudder inputs at the edge of the runway, the plane will be pointing 075° and will continue in that direction until I apply an opposite force to the inertia.

 

[vintage cessna]

Come down final runway 09 in zero wind conditions lined up centerline. Over the threshold I throw in a left slip and move it across the runway at an angle as demonstrated above of 15°. When I neutralize aileron and rudder inputs at the edge of the runway, the plane will be pointing 075° and will continue in that direction until I apply an opposite force to the inertia.

If your nose ends up at 075 it is because you did a slipping turn and not a side slip. Agree that direction of travel will continue at 075 momentarily, but once out of the slip no further control movements will be needed to overcome the inertia, the airplane will do that itself if controls are neutral.

 

[Henning]

If your nose ends up at 075 it is because you did a slipping turn and not a side slip. Agree that direction of travel will continue at 075 momentarily, but once out of the slip no further control movements will be needed to overcome the inertia, the airplane will do that itself if controls are neutral.

In order to move sideways in a zero wind condition, YOU MUST MAKE A SLIPPING TURN.

There is no such thing as a side slip or forward slip, there is only slip, and Zule... Next person that says "side slip" will be urged to a stone dog by Zule...

Unless you make a slipping turn, the flight path will not change in a slip. All you are doing is presenting the side of the plane to the relative wind.

 

[Silvaire]

...When I neutralize aileron and rudder inputs at the edge of the runway, the plane will be pointing 075° and will continue in that direction until I apply an opposite force to the inertia.

Henning you continue to ignore one aspect here. Are you trying to tell us that if you are in a slip it is impossible to move the controls to a neutral position and keep the nose on a constant heading at the same time? See my post above, I understand the relative wind in a slip factor but you don't have to simply let go of the controls. This, I suspect is the object of the constant heading side slip drill because it seems that those who have not done the exercise don't believe it's possible or even understand what's going on.

Also in regards to the constant arc theory, the rate gyro in the turn indicator would detect that and show you were in a turn. Anybody want to tag a second GoPro to their turn indicator while doing a prolonged slip?

 

[Henning]

Henning you continue to ignore one aspect here. Are you trying to tell us that if you are in a slip it is impossible to move the controls to a neutral position and keep the nose on a constant heading at the same time? See my post above, I understand the relative wind in a slip factor but you don't have to simply let go of the controls. This, I suspect is the object of the constant heading side slip drill because it seems that those who have not done the exercise don't believe it's possible or even understand what's going on.

Also in regards to the constant arc theory, the rate gyro in the turn indicator would detect that and show you were in a turn. Anybody want to tag a second GoPro to their turn indicator while doing a prolonged slip?

You are disregarding the conditions of "The Drill" You are missing that this guy took a normal drill and added impossible qualifications to it. It's the impossible qualifications you are ignoring, and Wifferdill and I have issue with.

 

[vintage cessna]

In order to move sideways in a zero wind condition, YOU MUST MAKE A SLIPPING TURN.

There is no such thing as a side slip or forward slip, there is only slip, and Zule... Next person that says "side slip" will be urged to a stone dog by Zule...

Unless you make a slipping turn, the flight path will not change in a slip. All you are doing is presenting the side of the plane to the relative wind.

You know, no one is trying to embarrass anyone or get one up. Some of us just couldn't let pass some of the basics being disputed that we thought were indisputable. We've tried to use logic and some authoritative sources to bolster our points.

But when you make these statements and put some of them in caps, you are just doing to yourself what we are trying not to do.