Takeoff with light quartering tailwind
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Takeoff with light quartering tailwind
What should be aileron position if you are taking off in light quareting tailwind? What i learned in CPL Days was...
for taxiing in light quartering tailwind (say from left) hold control wheel to the right so that my left ailerons are down and right ailerons are up. Does same thing hold good for takeoff also?
for taxiing in light quartering tailwind (say from left) hold control wheel to the right so that my left ailerons are down and right ailerons are up. Does same thing hold good for takeoff also?
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always into the wind.
Don't know what airplane you are flying, but beware of the fact that if you displace the yoke to far into the wind -> your spoilers will also come up -> causing more drag.
Don't know what airplane you are flying, but beware of the fact that if you displace the yoke to far into the wind -> your spoilers will also come up -> causing more drag.
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Further info
Referring to this webpage http://freepilotinfo.********.com/20...wind-taxi.html shows POH diagram for taxiing with tailwind. It says left quartering tailwind left aileron down. So why would it be different for takeoff?
If it is b737 what will be aileron position with light quartering tailwind?
Note: just insert word b-l-o-g-s-p-o-t in above weblink without dashes
If it is b737 what will be aileron position with light quartering tailwind?
Note: just insert word b-l-o-g-s-p-o-t in above weblink without dashes
Last edited by mfclearner; 11th Jan 2012 at 10:57. Reason: Adding more info
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Once the take off run is commenced then you do not have a tailwind in any real sense. The ground speed will be higher than your airspeed, but there is not wind coming from behind, and over, the tail and wings.
Control displaced when taxiing light aircraft can be "reversed", because at that stage there may be wind coming from behind, but this is quite different.
Wally.
Control displaced when taxiing light aircraft can be "reversed", because at that stage there may be wind coming from behind, but this is quite different.
Wally.
Thats a good way of explaining it Wally 
True ifly, but how far is 'too far' ? If you are looking at the aileron trim markings on the yoke in front of you, how many before the spoilers rise?
Don't know what airplane you are flying, but beware of the fact that if you displace the yoke to far into the wind -> your spoilers will also come up -> causing more drag.
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Went through the trouble of checking the AMM about this a while back for the 737, If I remember correctly the spoilers start to come up at 1.6 units on the yoke. Still - this is not a reason to limit aileron inputs if they are required...
Begin the takeoff roll with the control wheel approximately centered. Throughout
the takeoff roll, gradually increase control wheel displacement into the wind only
enough to maintain approximately wings level.
the takeoff roll, gradually increase control wheel displacement into the wind only
enough to maintain approximately wings level.
Excessive control wheel displacement during rotation and liftoff increases
spoiler deployment. As spoiler deployment increases, drag increases and
lift is reduced which results in reduced tail clearance, a longer takeoff roll,
spoiler deployment. As spoiler deployment increases, drag increases and
lift is reduced which results in reduced tail clearance, a longer takeoff roll,
and slower aircraft acceleration.
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Thanks
In the 727, the spoilers come up after the yoke is rotated 10 degrees. In the 747 for dummies manual I've got with me, it doesn't give a number, it just says the ailerons and spoilers work together for roll control. Hey, if it's not in the book, they can't ask about it on the oral.
In most transport airplanes you are limited to a 10 knot tailwind. You're going to change that around to a headwind before the power is even half way set.
In most transport airplanes you are limited to a 10 knot tailwind. You're going to change that around to a headwind before the power is even half way set.
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Throughout the takeoff roll, gradually increase control wheel displacement into the wind only enough to maintain approximately wings level.
You should start with it deflected and return to neutral as the airspeed increases so that you leave the runway wings level.
In the 727, the spoilers come up after the yoke is rotated 10 degrees.
You should start with it deflected and return to neutral as the airspeed increases so that you leave the runway wings level.
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Framer
I think you may have mis-read the book or are reading from the landing section where you increase aileron deflection as the speed decreases and the ailerons become less effective.
I find it hard to believe that Boeing would publish something like this. If you start at neutral and work into the wind as the airspeed increases you're trying to roll the airplane while it's still on the ground. This puts extra stresses on the landing gear and really stresses that work their way back to the wing root. Not to mention differential drag on the main landing gear causing a yaw in the direction of aileron deflection. So that takes care of the problems on the ground.
Now for the problems in the air. The ailerons work by changing the lift on the individual wings. Aileron down, increased angle of attack, more lift and vice versa. So as you get closer to Vr one wing will be making the lift required for rotation before the other. You can see where this is going. Now you have one wing flying and the other one...well...not. And since both wings are connected, with asymmetrical lift one goes up, the other goes down. And it's not long till the tip of the wing meets concrete and the insurance rate begins to climb.
The procedure for takeoff (this could be different in the bigger jets with roll spoilers and all that stuff, the biggest thing I've ever flown is a King Air) is to start with the ailerons deflected fully into the crosswind, whether it's a headwind, or tailwind, that doesn't matter, because like someone else said the tailwind is gone by the time the engine is halfway to takeoff power. As the airspeed increases you'll feel the control forces increase (hydraulic controls too? I think, dunno, never flown 'em) so you slowly "give in" to the suggestion the airplane is giving you and begin to return the control wheel to neutral. The goal should be to hit neutral just before rotation speed, pull the airplane off the runway, and adjust bank angle as appropriate.
I think you may have mis-read the book or are reading from the landing section where you increase aileron deflection as the speed decreases and the ailerons become less effective.
I find it hard to believe that Boeing would publish something like this. If you start at neutral and work into the wind as the airspeed increases you're trying to roll the airplane while it's still on the ground. This puts extra stresses on the landing gear and really stresses that work their way back to the wing root. Not to mention differential drag on the main landing gear causing a yaw in the direction of aileron deflection. So that takes care of the problems on the ground.
Now for the problems in the air. The ailerons work by changing the lift on the individual wings. Aileron down, increased angle of attack, more lift and vice versa. So as you get closer to Vr one wing will be making the lift required for rotation before the other. You can see where this is going. Now you have one wing flying and the other one...well...not. And since both wings are connected, with asymmetrical lift one goes up, the other goes down. And it's not long till the tip of the wing meets concrete and the insurance rate begins to climb.
The procedure for takeoff (this could be different in the bigger jets with roll spoilers and all that stuff, the biggest thing I've ever flown is a King Air) is to start with the ailerons deflected fully into the crosswind, whether it's a headwind, or tailwind, that doesn't matter, because like someone else said the tailwind is gone by the time the engine is halfway to takeoff power. As the airspeed increases you'll feel the control forces increase (hydraulic controls too? I think, dunno, never flown 'em) so you slowly "give in" to the suggestion the airplane is giving you and begin to return the control wheel to neutral. The goal should be to hit neutral just before rotation speed, pull the airplane off the runway, and adjust bank angle as appropriate.
My goodness you're authoritive for someone who has never flown the aircraft you are giving advice on.
Different machinary, different techniques required. Boeing did publish that,it is a direct cut and paste from the latest update
That aint gunna be pretty in a 737.
I think you may have mis-read the book or are reading from the landing section where you increase aileron deflection as the speed decreases and the ailerons become less effective.
I find it hard to believe that Boeing would publish something like this.
I find it hard to believe that Boeing would publish something like this.
The goal should be to hit neutral just before rotation speed, pull the airplane off the runway, and adjust bank angle as appropriate.
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Interesting. From the Flight Crew Training Manual for the 737-200 dated in 2005, it says simply "maintain wings level during the takeoff roll by applying control wheel displacement into the wind".
Bottums Up
An old instructor, ex RAAF - eccentric but a gifted instructor, taught that the ailerons are for roll control.
Therefore, if barrelling down the runway and the wind is not sufficient to cause any roll, leave ailerons neutral. If the wind is causing some roll (there won't be much because the darned thing's on the ground) only use enough aileron to keep wings level (ie, use the natural horizon).
Simple.
Therefore, if barrelling down the runway and the wind is not sufficient to cause any roll, leave ailerons neutral. If the wind is causing some roll (there won't be much because the darned thing's on the ground) only use enough aileron to keep wings level (ie, use the natural horizon).
Simple.