Stalls into a headwind or Tailwind

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astroguy
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Stalls into a headwind or Tailwind

Post by astroguy »

Hey... Just looking for some expertise here. It has come up recently that are little LSA ikarus tends to break a stall much cleaner when doing a Tailwind stall versus a headwind stall. However the relative wind indicated AirSpeed are both identical? Where am I wrong on this? In practice on this aircraft it's seems to be a real affect despite it not making sense. Thanks
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photofly
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Re: Stalls into a headwind or Tailwind

Post by photofly »

What answer are you hoping to hear?
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aeroncasuperchief
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Re: Stalls into a headwind or Tailwind

Post by aeroncasuperchief »

When landing into a strong tailwind as compared to a headwind ( whether or not you KNOW what the wind direction is ) you WILL have a poorer tailwind landing. I would imagine the same holds true with stalls etc !
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Re: Stalls into a headwind or Tailwind

Post by aeroncasuperchief »

What I am getting at here is the progression of steady state to wind increase to wind decrease in a gust ,, is reversed in its make-up in a tailwind and therefore is not an automatically conditioned response !
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Re: Stalls into a headwind or Tailwind

Post by astroguy »

photofly wrote: Fri Oct 26, 2018 5:51 pm What answer are you hoping to hear?
Really I am a low hour pilot and I am simply hoping to hear the correct answer. It could be an illusion however the light sport plane I fly regularly seems to mush into a strong headwind for a stall but we'll always stall with a Tailwind. And this doesn't make sense with relative wind.
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Re: Stalls into a headwind or Tailwind

Post by digits_ »

astroguy wrote: Fri Oct 26, 2018 6:44 pm
photofly wrote: Fri Oct 26, 2018 5:51 pm What answer are you hoping to hear?
Really I am a low hour pilot and I am simply hoping to hear the correct answer. It could be an illusion however the light sport plane I fly regularly seems to mush into a strong headwind for a stall but we'll always stall with a Tailwind. And this doesn't make sense with relative wind.
It doesn't matter. As you wrote yourself, the relative wind is the only thing that matters.

However, if you are, for whatever reason, focusing on the relative speed to the ground etc, and you want to get used to that, then it would make sense to always pick a headwind, or always pick a tailwind. Doesn't seem important to me, but maybe your instructor has a reason?

I liked doing slow flights and stall exercises on a day with a steady 40kt headwind, you could actually see the plane move backwards over the ground.
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Re: Stalls into a headwind or Tailwind

Post by photofly »

aeroncasuperchief wrote: Fri Oct 26, 2018 6:24 pm What I am getting at here is the progression of steady state to wind increase to wind decrease in a gust ,, is reversed in its make-up in a tailwind and therefore is not an automatically conditioned response !
We need pdw. Where are you?
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DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
I WAS Pez
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Re: Stalls into a headwind or Tailwind

Post by I WAS Pez »

photofly wrote: Fri Oct 26, 2018 7:09 pm We need pdw. Where are you?
Right!?

I saw the thread title, and though pdw...was surprised when it wasn't him.
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telex
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Re: Stalls into a headwind or Tailwind

Post by telex »

photofly wrote: Fri Oct 26, 2018 7:09 pm
aeroncasuperchief wrote: Fri Oct 26, 2018 6:24 pm What I am getting at here is the progression of steady state to wind increase to wind decrease in a gust ,, is reversed in its make-up in a tailwind and therefore is not an automatically conditioned response !
We need pdw. Where are you?
LOL.

7 meters per second from the southwest through 1500' shearing to 3 meters per second at an elevation of 452' will get you every time.
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Re: Stalls into a headwind or Tailwind

Post by Meatservo »

It's probably just an illusion created by the difference in groundspeed. There shouldn't be any difference in how the plane behaves.
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Re: Stalls into a headwind or Tailwind

Post by AuxBatOn »

Looking at your video in another post, your longitudinal aft stick input is a lot more abrupt and fast during your tailwind stall, which mat explain why you feel that way. Steady winds have no effects on stall characteristics.
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Last edited by AuxBatOn on Sat Oct 27, 2018 6:01 am, edited 1 time in total.
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Re: Stalls into a headwind or Tailwind

Post by fish4life »

aeroncasuperchief wrote: Fri Oct 26, 2018 6:19 pm When landing into a strong tailwind as compared to a headwind ( whether or not you KNOW what the wind direction is ) you WILL have a poorer tailwind landing. I would imagine the same holds true with stalls etc !
That’s due to the ground speed you touch down at, faster you are going the quicker the spool up on the tires has to be as well as any correction to slight yaw you may have landed with. It’s just like how a wet runway makes landings smoother.
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Re: Stalls into a headwind or Tailwind

Post by Zaibatsu »

Was it a variable tailwind?

Because that will definitely negatively affect the stall characteristics.

It’s perhaps one of the deadliest things we deal with in aviation.
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Re: Stalls into a headwind or Tailwind

Post by aeroncasuperchief »

"That’s due to the ground speed you touch down at, faster you are going the quicker the spool up on the tires has to be as well as any correction to slight yaw you may have landed with. It’s just like how a wet runway makes landings smoother."

Of course I am not talking about touchdown but rather just before it WHEN you get a gust !
When one considers a gust of wind, does the increase in wind speed equal the decrease in wind speed over time throughout the cycle?

Imagine a graph with the wind speed along the vertical and the time along the horizontal, the rise in the line to peak wind speed will be different than its decline back to steady state wind
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telex
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Re: Stalls into a headwind or Tailwind

Post by telex »

Zaibatsu wrote: Sat Oct 27, 2018 8:56 am Was it a variable tailwind?

Because that will definitely negatively affect the stall characteristics.

It’s perhaps one of the deadliest things we deal with in aviation.
A tailwind? Wha?
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Re: Stalls into a headwind or Tailwind

Post by 7ECA »

Not just a tailwind telex, a variable tailwind. Those 'suckers have taken down just about every type imaginable, heck they're about as bad as the Bermuda Triangle - which has been very quiet recently...

It's a pdw reference if you recall the odd chap. Probably a bit like Geoffrey Pyke, minus the pykrete.
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Re: Stalls into a headwind or Tailwind

Post by rookiepilot »

Is this before or after toking up?
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Re: Stalls into a headwind or Tailwind

Post by KAG »

I would think stalling into a headwind would recover cleaner then a tailwind, but all I've done over the last 15 years is avoid them (stalls) in the sim. I can honestly say from my training / instructing days this topic never came up.
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Re: Stalls into a headwind or Tailwind

Post by Old Dog Flying »

Get another instructor! The airplane does not know or care which way the win is blowing when doing stalls. It all depends on your entry technique.

After 40 years of instructing, I thought that I had heard it all. Now tell me, is there Yaw in turn? Or only in a LSA
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Re: Stalls into a headwind or Tailwind

Post by astroguy »

Wow... what a great resource of information folks. Thanks for all inputs.
I am sure that the phyics of the relative wind does not change either way.... and upon reflection I figure that there is a human factor going on here as mentioned ...
I'll be up on Tuesday and if enough wind I will do 10 upwinds and 10 downwinds and try for exact repetion.... I'll get back to you on that one.
The only thing keeping me going on this was a pilot who has flown this particular LSA for over 900 hrs did agree with my about its unusaul stall characteristics..... so I'm off to the skies this week,
Thanks again for the interest
DaveP
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