Question: Landing tail-wheel aircraft in a tail wind

[Centaurus]

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?

[tinpis]

It would take a massive skill failure to ground loop a Citabria in any conditions :hmm:

[avnut]

I guess once the tailwind component exceeds forward speed the wind could catch the deflected rudder and push the tail the opposite way to what's intended...?

[ForkTailedDrKiller]

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! :E

Dr :8

PS: Fortunately the rudder saved the day - working in the correct sense!

[Mark1234]

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..)

[djpil]

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 .....

[tinpis]

Anyway, the toebrakes still work (and in the correct sense..)

Yes, there's nothing quite as frightening as the old reverse sense toes brakes syndrome, its right up there with a Thronomister failure. :hmm:

[chimbu warrior]

Question: Landing tail-wheel aircraft in a tail wind

Just one question............why?

[ForkTailedDrKiller]

Just one question............why?

Hmm! Well in my case - landing the other way was kinda scarey due to the geography and various man-made obstructions, and I failed to detect the big gust that hit me up the arse when I least expected it! :E

Dr :8

[PyroTek]

10-12kt tailwind wouldn't be enough to overpower slipstream effect, even at idle power, would it?:sad:
Maybe he ground looped it trying to turn and stop before the end of the runway:ok:
Pyro

[185skywagon]

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

[Runaway Gun]

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.

[ForkTailedDrKiller]

since one can plant the mains at any speed.Plant Plant Plant Plant Plant Plant Plant

:E

[185skywagon]

Not me, Doc. And I never will again......

[M14_P]

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....:ugh:

[baron_beeza]

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 ??
:yuk:

[185skywagon]

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.

[Super Cecil]

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.


Agreed doesn't matter how much is discussed/flight sim'd/read, doing it is the only way. It can even vary between aircraft of the same type. Downwind landings are used a lot on AG op's.

[Andy_RR]

... 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.

What is plan B on a one-way strip? :confused:

[PyroTek]

What is plan B on a one-way strip? http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gifHope?:ok:..............

[osmosis]

see post #17....... (extending out to at least 10 characters)

[Murray Cod]

I've landed a 185 downwind once , the reason not for an into wind landing was oil all over the windscreen and a blinding afternoon sun,making it very very hard to see anything,i'll take the oil/sun route next time.
MC

[osmosis]

I'm silently hoping all of you who have spent any time in a 180/5 have done some tailwind time in same. Can't imagine anyone NOT having done so.

I'm never quite sure when you barstards are kidding.

[185skywagon]

Osmosis,
I have done a fair bit of both 185 time and tailwind landings. I just not that good at explainig things, otherwise I'd be an instructor. If you think I am kidding about anything , please say so.
185.

[Chimbu chuckles]

Well I have done probably 1000's of downwind landings in C185s in PNG...and 1000s more in Islanders and Twin Otters. My first base in PNG, Kundiawa, was a 1000m one way strip that 'enjoyed' 10-15kt quartering tailwinds from mid/late morning - essentially every day. Once I got a handle on the aircraft it barely raised a ripple on my otherwise calm visage. I am prepared to admit however that the first little while (I had <400TT starting out) was BLOODY hard on my adrenaline glands:ooh:

In fact virtually all one way mountain strips had tailwinds (adiabatic) from mid/late morning every day.

Maybe my experience has no relevance to the case at hand...10-15 sectors a day/6 days a week, on strips where going around for another try is out of the question, at or above MGW, makes you VERY good at putting the main wheels pretty damn close to EXACTLY where they need to go every time - Its far removed from a weekend pilot landing a Citabria downwind because he just didn't pay sufficient attention.

Plan B on a one way strip?

Well on PNG one way strips plan B was usually crashing into the jungle very nearby.

But having said all that a tailwind overpowering the rudder is NOT a reversal of rudder effect.

[185skywagon]

Plan b, for me, is simply having a point at which you can break off before you totally committed. Anything wrong with that? Each to their own.

[Chimbu chuckles]

Of course not 185skywagon:ok:

There are obviously commit points on any strip but in PNG but they were often a relatively long way out due terrain - as much as a nm or more. One strip I remember you were committed from that far out but couldn't see the strip until very short final.

[tinpis]

Yeah Chimbu (the airstrip) was a choppy bugger on approach.
Special fun in a short nose 402 with aft CG. :ooh:

[FlyingKiwi_73]

I see Ag guys (well one in particular) landing in tail winds all the time, cuts down on the ground time between dumps. seems to work fine in an ag wagon,... but then again the pilot is a very talented chap.

[Goat Whisperer]

take a look at a rudder/fin, bird's eye view, imagine the airflow, conventional, from front to aft, and the resultant force/moment.

Reverse that airflow and the yaw force/moment will still be the same way.

Don't know how you get the control reversal hypothesis.

[Stationair8]

Watched an Ag pilot in a Pawnee a few months ago, go about his business, land with a 10-15kt tailwind going uphill, load up depart into wind going downhill operate within a two or three mile radius of the aerodrome repeat exercise numerous times until moning smoko. After smoko, seabreeze had moved in now landing with a 15-20knot headwind uphill, departing downhill with a tailwind, repeat exercise until lunchtime. After lunch the seabreeze had swung around and now landing with a quartering headwind and departing with a quartering tailwind, repeat until afternoon smoko.

The only thing I noticed was on a downwind take-off he would hold the stick to the left, with the wind coming from the right hand side.

Every landing was within a few feet of the previous touchdowns, roll to halt, loadup and go, why waste your time going to an airshow, when you watch that for free.

The other thing was that the guy still gave all the radio calls, and worked around the various RPT arrivals and departures.

[djpil]

Reverse that airflow and the yaw force/moment will still be the same way.It won't be actually.

Try tailsliding an aeroplane and see the response to controls although you don't need to go to that extreme - just draw a picture then imagine Newton and Bernoulli at play.