Great Ozzie I think im getting my left and rights confused again re crosswind direction... Basically left ailerons with right rudder and vice versa.

Reading this thread, I am getting slightly confused.

taking off, with a crosswind from left to right, the wind pushes my tail (specifically my vertical stabilizer) and as a result, my plane begins point into the wind. I am not sure what this phenomenon is called, but I'd like to know.

To counter this, I apply right rudder, causing a yaw to the right, theoretically keeping my plane pointing straight down the center line.

Is this right? using my ailerons to create a bank to the (left?) would also help?

I think im getting my left and rights confused again re crosswind direction... Basically left ailerons with right rudder and vice versa.

 

Just remember... turn into the wind with ailerons and rudder to straighten the nose... whatever is needed.

 

If the wind was pushing you right of center... well... you would not bank to the right as that would take you further from the runway.

 

So you bank to the left the amount needed to stop drift... then you have to use that right rudder (some) to keep from turning left.

 

===============

 

It's called Weathervaning, Matt (like a weathervane on a barn etc.)

 

To counter this, I apply right rudder, causing a yaw to the right, theoretically keeping my plane pointing straight down the center line.

Is this right? using my ailerons to create a bank to the (left?) would also help?

 

Yes all correct... and in a real aircraft you will need "more" right rudder than normal (for the takeoff roll) to compensate for the left x-wind.

 

You are correct, they ring every once of performance out of the plane when certifying it.

 

This is wrong with respect to what is stamped on the "demonstrated x-wind" as it could in fact be much higher than this.

 

And I must say Bob... just because you do not know something or have not been taught something... then to imply I am an unsafe pilot because of your misunderstanding or lack of knowledge... is wrong of you and not at all appreciated. You are going to have a tough time finding an instructor that places a higher premium on safety (than myself).

Reading this thread, I am getting slightly confused.

taking off, with a crosswind from left to right, the wind pushes my tail (specifically my vertical stabilizer) and as a result, my plane begins point into the wind. I am not sure what this phenomenon is called, but I'd like to know.

To counter this, I apply right rudder, causing a yaw to the right, theoretically keeping my plane pointing straight down the center line.

Is this right? using my ailerons to create a bank to the (left?) would also help?

 

It is called weather vaning . This will happen on a nose wheel plane, as soon as you rotate. I just let the nose swing to the left, and use the ailerons to track straight down the runway. This is made worse of course with a left crosswind plus the asymmetrical thrust of the clockwise rotating prop.

Thanks for the help

Welcome bakka... I hope it is a bit more clear... if not continue to ask and let's work this out.

 

-Rob

 

I expect that the test pilot (an employee of the aircraft builder?) is... encouraged... to maximize the performance of the aircraft.

 

It could be during testing (pre-certification) the manufacturer did want to know the "max" the aircraft was capable of... "yeah 25kts is doable, but I think way outside what an 'average' pilot is typically capable of".

 

Or maybe, "Can it handle 15kts?" "Yeah 15kts is no problem" And the application made for 12kts (who knows why? except that is what the manf. wanted).

 

Again this applies specifically to max demonstrated crosswind... not Vne.. not Va... not stall speeds... not g's it is certificated for... not anything else.

It is called weather vaning . This will happen on a nose wheel plane, as soon as you rotate. I just let the nose swing to the left, and use the ailerons to track straight down the runway. This is made worse of course with a left crosswind plus the asymmetrical thrust of the clockwise rotating prop.

Thanks Bob, now I know...weather vaning. This sounds like paddling a canoe, alone, wrongly positioned in the stern, on a windy day. Your body weight creates a pivot point in the water, and the bow of the canoe will always try to point away from the wind, making steering difficult. Same phenomenon, except with nose wheel planes the pivot is at the bow, not the stern.

I am not sure how ailerons will help keep the aircraft on center line though....I am sure this will happen, I am just trying to understand the forces at work...I thought ailerons only create localized drag, and therefore bank left or right. Brain...trying....to...understand....

This is wrong with respect to what is stamped on the "demonstrated x-wind" as it could in fact be much higher than this.

 

And I must say Bob... just because you do not know something or have not been taught something... then to imply I am an unsafe pilot because of your misunderstanding or lack of knowledge... is wrong of you and not at all appreciated. You are going to have to have a tough time finding an instructor that places a higher premium on safety (than myself).

 

First of all, I didn't say that "you" were an unsafe pilot. What I did say is that I personally don't fly with pilots that ignore things like demonstrated crosswind components, telling me that they personally are capable of handling more than that.

The demonstrated means that the aircraft was demonstrated to be able to handle that amount of crosswind safely. Could it handle more, probably, but I think the average pilot probably wouldn't want to be flying in that region, because you still have to factor in gusts that may exceed that value that come along at the wrong moment. I tend to fly by the book, and don't try to push the envelope.

 

Thanks Bob, now I know...weather vaning. This sounds like paddling a canoe, alone, wrongly positioned in the stern, on a windy day. Your body weight creates a pivot point in the water, and the bow of the canoe will always try to point away from the wind, making steering difficult. Same phenomenon, except with nose wheel planes the pivot is at the bow, not the stern.

I am not sure how ailerons will help keep the aircraft on center line though....I am sure this will happen, I am just trying to understand the forces at work...I thought ailerons only create localized drag, and therefore bank left or right. Brain...trying....to...understand....

 

Canoes scare me, they tip over to easily...... I may be wrong, but I think the aileron keeps the upwind wheel pressed onto the runway, and also keeps the wind from getting under the wing and lifting it. This lifting of the upwind wing, in a high wing aircraft is even worse, so when taxiing, you have to make sure controls are positioned correctly in heavy winds. If the wind is from your left rear, you want the control opposite or pushed to the right front. Right rear, left front, keeps the wind from getting under the rear stabilizer that way.

 

see figure 5-4.

 

 

http://avstop.com/ac/flighttrainghandbook/taxiinggeneral.html

I thought ailerons only create localized drag, and therefore bank left or right. Brain...trying....to...understand....

 

Matt... you understand a side-slip right (no wind). Airplane banked one way and opposite rudder. The plane (if enough aileron) will track diagonally in the direction of the bank...

 

So if you add in wind (say from the left) and you are tracking left.. they can (can) cancel each other out.

I would not expect ANY statistic that's going to end up in marketing literature (to be compared against other aircraft when making a purchase decision) to be conservative. You can assume anything you want; I'm going to assume the pilot was pushing the envelope. Also, the idea that just because the word "demonstrated" was used means that the number was not a maximum is semantics, not safety. Is the plane capable of higher crosswinds? Who cares? If you want to go out to test it, I'll watch from the safety of the ground.

 

Hook

First of all, I didn't say that "you" were an unsafe pilot.

 

No but it was implied as I said... as if I am some sort of "bold" pilot.

 

What I did say is that I personally don't fly with pilots that ignore things like demonstrated crosswind components,

 

I don't ignore it... you are most incorrect there. I fly by the book... but I also know my aircraft.

 

The demonstrated means that the aircraft was demonstrated to be able to handle that amount of crosswind safely.

 

Again... if you are trying to say that is all it will handle safely... you are wrong. Period.

 

telling me that they personally are capable of handling more than that.

 

Can... and am... and just because you never had anyone teach you this... does not automatically put it into the realm of "unsafe".

 

In fact... that is the whole point. Safety! To know what you can and cannot do safely.

 

So go back and learn what it means... then make your proclamations of what is safe and not safe.

Matt... you understand a side-slip right (no wind). Airplane banked one way and opposite rudder. The plane (if enough aileron) will track diagonally in the direction of the bank...

 

So if you add in wind (say from the left) and you are tracking left.. they can (can) cancel each other out.

 

OK, I just did that on paper with stick drawings and it's making sense now. Now to go home and feel it working in the game!

 

Thanks!

Welcome, Matt... glad it makes more sense.

 

Is the plane capable of higher crosswinds? Who cares?

 

You might one day when you have been practicing with nothing but 10 or so knots xwind... then one day find yourself in conditions that exceed this.

 

Now there is one thing I do not do, Hook... make assumptions about this or that.

 

Also, the idea that just because the word "demonstrated" was used means that the number was not a maximum is semantics, not safety.

 

Wrong, wrong, wrong... but if you wish to assume this... of course it is up to you.

I think we are all talking past one another in the interest of safety.

 

if you are trying to say that is all it will handle safely... you are wrong.

 

I think he's saying that's all he knows it will handle safely. I don't think anyone is saying that is all it can handle.

 

A big part of becoming comfortable with an aircraft is pushing it's limits, so you know exactly what they are, how to recognize you are approaching them, and how to bail yourself out of trouble if you exceed them to the point of danger. And as you become more comfortable with the aircraft, the limits tend to push back a bit. But anything placarded in the cockpit is a good starting point for identifying limits.

 

And as a low-time pilot who knows not to push his own limits too far, that's all I have to say about that. :p0504:

As John King would say in his "King" instruction videos....

 

"If you don't have enough rudder to align the nose with the runway, then go somewhere else."

 

And, that's the bottom line. If the nose isn't straight with the runway on touchdown, you'll get side loads on the landing gear. If the nose isn't aligned with the runway on a taildragger, it can be worse, as the back end will want to swing around to the front position. Nose wheel airplanes inherently try to re-align themselves with the runway. That's the crosswind/nose wheel advantage. Nose wheels just don't usually do as well in rough runway conditions, as they're also good at tucking under, and causing a prop strike.