Crosswind Takeoff 33kts 737NG

[Driver 170]

With a XW off 33kts right on the limit how much rudder control does it take to keep the nose pointing down the Centreline? Do you use the Tiller Steering during the initial part of the takeoff run (upto 40kts)

Thanks

[Johnny F@rt Pants]

You use sufficient rudder to keep the aeroplane tracking down the centreline, it’s almost impossible to quantify how much that is.

There is no need to use the tiller, you might be in the right hand seat which might not have a tiller.

[billovitch]

And as you rotate, if you release the rudder gently the aircraft weathercocks into wind and you have the drift corrected for the initial flight phase.
Into wind aileron is also required during the ground run in strong xw.

[BraceBrace]

Rudder is connected to the nose wheel steering so there is no point in using the tiller, it would only be a very uncomfortable ride.

Rudder deflections are more like "kicks" because it is a search for some kind of balance with changing winds. Once beyond 80kts, the aileron (control wheel) should come in which is - unlike the rudder - a constant deflection. You would notice the required rudder pedal "kick amplitude" is reduced as more and more aileron is put in. At a certain control wheel displacement (aileron deflection), the ailerons cancel out almost all of the required rudder pedal deflections. That's when aileron input is correct and you can rotate without wingdrop (which is to be avoided on the B737).

[Johnny F@rt Pants]

At a certain control wheel displacement (aileron deflection), the ailerons cancel out almost all of the required rudder pedal deflections. That's when aileron input is correct and you can rotate without wingdrop

Am I reading this right BB? Are you saying that as you input aileron into wind you have to reduce the rudder input as the aileron input means the rudder isn’t required?

[BraceBrace]

The rudder is the tool to track centerline, the ailerons the tool to keep wings level during rotation.

The ultimate end goal is to make a rotation absolutely wings level. For this you need correct aileron input from the start of the rotation, with nose gear still on the ground. How much? After 80kts, slowly increase control wheel deflection untill rudder deflection "amplitude" is minimal. You will still be "kicking the rudder" to track your centerline, but the kicking will be very very minimal.

If you fly the B737 just try it. Correct aileron reduces required rudder for centerline tracking.

[billovitch]

But the rudder is applied out of wind.
This prevents the weathercock effect.
The aileron is applied into wind.
This keeps the aircraft weight evenly distributed and prevents wing lift.

Wind from left - rudder right - ailerons left.
That’s on the ground.

Once in the air rudder should be zero - if you release gently just as you rotate, the weathercock is allowed to occur - which effectively compensates for drift.
The aileron input should be taken out at this time too. During the weathercocking there will be a roll couple and releasing the aileron input compenstates this to some extent.

[Driver 170]

This is all interesting for a enthusiast. I have been reading the FCTM from Boeing but its great to hear mixed operational experiences from line pilots.

Now the tricky part using the rudder is for De-Crab during flare at approximately 20ft as you retard the Thrust levers and hold that pitch. Must take some considerable practice. I know most airlines don’t allow new Cadets with certain wind factor and hours on type to do any crosswind landing or takeoff

[chevvron]

When I was working at Sumburgh back in 1972, I returned from lunch to find a piece of paper on the controllers desk with '160/18' written on it.
I was told that it was the wind direction/speed which I had to pass to the pilot of the BEA Viscount which was due to depart shortly.
No I don't remember what the wind actually was but it wasn't 160/18!!

[Johnny F@rt Pants]

Now the tricky part using the rudder is for De-Crab during flare at approximately 20ft as you retard the Thrust levers and hold that pitch. Must take some considerable practice. I know most airlines don’t allow new Cadets with certain wind factor and hours on type to do any crosswind landing or takeoff

It’s not tricky at all really, but it does take some practice. You flare as normal at circa 20’ still crabbed, then retard the thrust levers then as you are about to “impact” the runway you squeeze the appropriate rudder pedal to align the aeroplane with the rudder, you must also apply the opposite aileron to prevent the roll effect of the rudder input.

[Johnny F@rt Pants]

When I was working at Sumburgh back in 1972, I returned from lunch to find a piece of paper on the controllers desk with '160/18' written on it.
I was told that it was the wind direction/speed which I had to pass to the pilot of the BEA Viscount which was due to depart shortly.
No I don't remember what the wind actually was but it wasn't 160/18!!

I vividly remember my first landing in Sumburg, it was dark so we couldn’t use runway 15, 09 it was then, with a lovely wind of 160/33 gusting more than double that!! It were a bit rough!!