Question: Landing tail-wheel aircraft in a tail wind
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Question: Landing tail-wheel aircraft in a tail wind
Latest issue of the magazine "Australian Flying" (March-April 2011) features a regular flight safety column by South African pilot, Jim Davis. See page 75.
He reports on a Citabria that ground-looped while landing in a 10-12 knot tailwind. What had me mystified was part of his report which stated:
"The rudder steers a taildragger on the ground, but for it to work properly the wind must come from the front. As the aeroplane slows down the rudder gets less effective and eventually starts working in reverse - right rudder turns you left. So the groundloop was not surprising."
I have flown a few taildraggers in another life but cannot recall the rudders working in reverse as the aircraft slows down.
Can someone please explain the rudder in reverse theory, put forward by Jim Davis?
He reports on a Citabria that ground-looped while landing in a 10-12 knot tailwind. What had me mystified was part of his report which stated:
"The rudder steers a taildragger on the ground, but for it to work properly the wind must come from the front. As the aeroplane slows down the rudder gets less effective and eventually starts working in reverse - right rudder turns you left. So the groundloop was not surprising."
I have flown a few taildraggers in another life but cannot recall the rudders working in reverse as the aircraft slows down.
Can someone please explain the rudder in reverse theory, put forward by Jim Davis?
One of only two occassions that I have been close to bending an aeroplane was landing a C185 with a tailwind.
Oh, but that was cause I ran out of runway!
Dr
PS: Fortunately the rudder saved the day - working in the correct sense!
Oh, but that was cause I ran out of runway!
Dr
PS: Fortunately the rudder saved the day - working in the correct sense!
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Quite - with sufficient tailwind you'd maybe have reverse flow over the rudder - notwithstanding any propwash. In my humble opinion, the chances of that providing sufficient reverse control to effect a groundloop - minimal. I'd be more concerned about the earlier reduction in effectiveness in it's normal operation. Anyway, the toebrakes still work (and in the correct sense..)
Sometimes Mr Davis just seems to get way off track.
10 kts of wind from the rear vs some little forward speed plus a little bit of propeller slipstream still equates to forward airspeed over the tail. True that the tailwind results in less airflow over the tail so that in itself is a factor
I wonder if he was thinking of this scenario - tailwind so a long float - try to get it on the ground but still going fast as it touches down - stick a long way from back - perhaps the stick even bounced forward as the tail came down - he/she doesn't do anything about moving the stick back further - no load on the tailwheel so not much directional control as the airspeed reduces .....
10 kts of wind from the rear vs some little forward speed plus a little bit of propeller slipstream still equates to forward airspeed over the tail. True that the tailwind results in less airflow over the tail so that in itself is a factor
I wonder if he was thinking of this scenario - tailwind so a long float - try to get it on the ground but still going fast as it touches down - stick a long way from back - perhaps the stick even bounced forward as the tail came down - he/she doesn't do anything about moving the stick back further - no load on the tailwheel so not much directional control as the airspeed reduces .....
Silly Old Git
Anyway, the toebrakes still work (and in the correct sense..)
Just one question............why?
Dr
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10-12kt tailwind wouldn't be enough to overpower slipstream effect, even at idle power, would it?
Maybe he ground looped it trying to turn and stop before the end of the runway
Pyro
Maybe he ground looped it trying to turn and stop before the end of the runway
Pyro
There are times when operating with tailwinds on landing, are unavoidable. Ag- ops for eg. It just requires a bit more focus. There should be no reason to float in a t/w aircraft, since one can plant the mains at any speed. My 2cents.
185
185
I'm concerned that some people are over calculating just how much thrust their prop puts out at idle...
Twelve knots of tailwind is quite a lot, and in a bulk package. Whereas an idle slipstream is minimal in comparison.
Twelve knots of tailwind is quite a lot, and in a bulk package. Whereas an idle slipstream is minimal in comparison.
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Why do so many people spend so much time working out which rudder and how much they need before they get into the aeroplane?
Fly it with your ass and use what you need to keep it STRAIGHT.
Going back to the point, a tailwind landing was the time I had my scare, in a Pitts. It probably wasn't as big a deal as I made it out to be but it caught me well off guard that's for sure, because I hadn't checked the windsock out to notice the windchange....
Fly it with your ass and use what you need to keep it STRAIGHT.
Going back to the point, a tailwind landing was the time I had my scare, in a Pitts. It probably wasn't as big a deal as I made it out to be but it caught me well off guard that's for sure, because I hadn't checked the windsock out to notice the windchange....
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It can be difficult planting the mains in a taildragger in a tailwind situation. We are generally talking one-way strips which often have a slope to aid the shorter length.
The trap is the negative wind gradient effect encountered on short finals, - the airspeed is trying to increase just as you are endeavouring to wash off the speed.
The tendency is then to throw the mains on the ground, in turn leading to a bounce.... and another etc.
The tailwind chews the remaining runway up very quickly, the bloody wheel brakes aren't working from 3 feet up.... oh s**t....
Nowhere to go, one-way strip..
Finally on the deck, no runway left, too fast to brake before the end....
panic.... hard on one rudder/brake(even harder) and prevent the over-run..
Phew... made it.. !!
(in a fashion..)
That wasn't so scary was it pax ??
The trap is the negative wind gradient effect encountered on short finals, - the airspeed is trying to increase just as you are endeavouring to wash off the speed.
The tendency is then to throw the mains on the ground, in turn leading to a bounce.... and another etc.
The tailwind chews the remaining runway up very quickly, the bloody wheel brakes aren't working from 3 feet up.... oh s**t....
Nowhere to go, one-way strip..
Finally on the deck, no runway left, too fast to brake before the end....
panic.... hard on one rudder/brake(even harder) and prevent the over-run..
Phew... made it.. !!
(in a fashion..)
That wasn't so scary was it pax ??
I generally wouldn't land downwind with pax anyway only on Ag-type ops. No probs putting mains on in the 185.
baron, I mainly deal with fairly flat country, where you can go ahead and go around. Different story on a true one way strip.
Just to clarify, that it can be a dangerous practice if you don't have a plan B organised if things aren't looking right.
baron, I mainly deal with fairly flat country, where you can go ahead and go around. Different story on a true one way strip.
Just to clarify, that it can be a dangerous practice if you don't have a plan B organised if things aren't looking right.
Last edited by 185skywagon; 24th Feb 2011 at 03:09. Reason: clarification
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Why do so many people spend so much time working out which rudder and how much they need before they get into the aeroplane?
Fly it with your ass and use what you need to keep it STRAIGHT.
Fly it with your ass and use what you need to keep it STRAIGHT.
Last edited by Super Cecil; 24th Feb 2011 at 03:11. Reason: to optimize dynamic abstractions
