RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Downwind turn Myth

Reply
Old 06-29-2011, 08:12 PM
  #976
RZielin
 
Join Date: Jun 2009
Location: Madbury, NH
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

OK, why is everyone too lazy to do the obvious?

Someone, PLEASE, make a little simulator video!!!

Set up a 20 kt wind right down the runway. Fly a cub in an oval circuit just above "stall speed" (I know, I know, there's no such thing as stall "speed", only stall AOA).

I think you can even do it with the little window that shows stick movements, can't you?

Then everyone can see the proof with their own eyes. The plane will NOT lose any more altitude turning downwind than turning upwind. At least not if the pilot keeps stick movements pretty much the same both ways. As I have said before, the turns will LOOK very different at each end of the circuit if stick movements are the same, and if you keep your thumb off the throttle.

Just don't anyone do it until we hit 1000, OK?

I admit I'm too lazy to do it. (Unless maybe the dinner offer applies to simulator videos too). I much prefer this armchair philosophizing. Seems to make time stand still, no?

#971 and honored to be part of the grand campaign to "1000"
RZielin is offline  
Reply With Quote
Old 06-29-2011, 08:16 PM
  #977
BlueBus320
 
Join Date: Mar 2002
Location: Rockville Centre
Posts: 1,524
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

It's funny hearing people talking about turning into or out of a steady state wind..lol. Kinda defeats the whole point.. You take off into the wind and once airborne, there is no down wind.
BlueBus320 is offline  
Reply With Quote
Old 06-29-2011, 08:16 PM
  #978
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
OK, why is everyone too lazy to do the obvious?

Someone, PLEASE, make a little simulator video!!!

Set up a 20 kt wind right down the runway. Fly a cub in an oval circuit just above "stall speed" (I know, I know, there's no such thing as stall "speed", only stall AOA).

I think you can even do it with the little window that shows stick movements, can't you?

Then everyone can see the proof with their own eyes. The plane will NOT lose any more altitude turning downwind than turning upwind. At least not if the pilot keeps stick movements pretty much the same both ways. As I have said before, the turns will LOOK very different at each end of the circuit if stick movements are the same, and if you keep your thumb off the throttle.
It's because those who don't want to believe now won't believe a vid either...they'll pick apart the software or something else rather than suffer the indignity of admitting they were wrong all along.
highhorse is offline  
Reply With Quote
Old 06-29-2011, 08:27 PM
  #979
RZielin
 
Join Date: Jun 2009
Location: Madbury, NH
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse

Quote:
OK, why is everyone too lazy to do the obvious?

Someone, PLEASE, make a little simulator video!!!

Set up a 20 kt wind right down the runway. Fly a cub in an oval circuit just above ''stall speed'' (I know, I know, there's no such thing as stall ''speed'', only stall AOA).

I think you can even do it with the little window that shows stick movements, can't you?

Then everyone can see the proof with their own eyes. The plane will NOT lose any more altitude turning downwind than turning upwind. At least not if the pilot keeps stick movements pretty much the same both ways. As I have said before, the turns will LOOK very different at each end of the circuit if stick movements are the same, and if you keep your thumb off the throttle.
It's because those who don't want to believe now won't believe a vid either...they'll pick apart the software or something else rather than suffer the indignity of admitting they were wrong all along.
highhorse, do NOT lose faith in humanity!


A sublime faith in human imbecility has seldom led those who cherish it astray.
Henry Ellis

RZielin is offline  
Reply With Quote
Old 06-29-2011, 08:32 PM
  #980
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

I posted months ago about having actually done 3 consecutive 360's into and out of a 100+ knot wind (well over 200 kts cumulative groundspeed difference) in a 320,000 lb airplane that was within 30 kts of stall speed for those conditions. Once established in the turn, with a million $$ worth of auto pilot doing the flying so I could stay kicked back and relaxed.....

Nothing. No trim changes, no throttle changes, NO AIRSPEED CHANGES......nothing. Why? Cus what I said in post #1 is absolutely true. An airborne aircraft is completely unaffected and doesn't give s sh^t where the (steady state) wind is from. PERIOD. If that weren't the case then I'd have been 170kts below stall speed when downwind and would not be alive to type here in this thread.

What else is there to talk about?


highhorse is offline  
Reply With Quote
Old 06-29-2011, 08:41 PM
  #981
BlueBus320
 
Join Date: Mar 2002
Location: Rockville Centre
Posts: 1,524
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Not to mention we all take advantage of the jet stream. That can be 200kts on the tail. You don't stall, just go REALLY fast
BlueBus320 is offline  
Reply With Quote
Old 06-29-2011, 09:13 PM
  #982
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
highhorse is offline  
Reply With Quote
Old 06-29-2011, 10:53 PM
  #983
Moerig
 
Join Date: May 2008
Location: , NAMIBIA
Posts: 303
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
I dont get that one, never seen a pelican do it so it cannot be safe....also turning in/out of a jetstream is not a steady state condition. Once in it it may be. For safety we always fly into a jetstream, it does slow you down a bit but at least you dont have to turn downwind.
And dont try this in a simulator, its not the same either. Real planes use airmolecules, FS uses electrons which can turn a lot easier and travel faster.
Moerig is offline  
Reply With Quote
Old 06-29-2011, 11:28 PM
  #984
roger.alli
 
roger.alli's Avatar
 
Join Date: Aug 2008
Location: Sydney NSW , AUSTRALIA
Posts: 932
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Just to keep the post count up.

http://www.youtube.com/embed/2eYoymfSqN0"

These guy know aerodynamics.

roger.alli is offline  
Reply With Quote
Old 06-30-2011, 12:12 AM
  #985
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
I dont get that one, never seen a pelican do it so it cannot be safe....also turning in/out of a jetstream is not a steady state condition. Once in it it may be. For safety we always fly into a jetstream, it does slow you down a bit but at least you dont have to turn downwind.
And dont try this in a simulator, its not the same either. Real planes use airmolecules, FS uses electrons which can turn a lot easier and travel faster.
I'm gonna give u the benefit of the doubt and assume ur kidding? It's getting pretty hard to tell...........
highhorse is offline  
Reply With Quote
Old 06-30-2011, 03:41 AM
  #986
Moerig
 
Join Date: May 2008
Location: , NAMIBIA
Posts: 303
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse


Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
I dont get that one, never seen a pelican do it so it cannot be safe....also turning in/out of a jetstream is not a steady state condition. Once in it it may be. For safety we always fly into a jetstream, it does slow you down a bit but at least you dont have to turn downwind.
And dont try this in a simulator, its not the same either. Real planes use airmolecules, FS uses electrons which can turn a lot easier and travel faster.
I'm gonna give u the benefit of the doubt and assume ur kidding? It's getting pretty hard to tell...........
Ok, I am kidding about the pelicans...

JUST 20 POSTS TO GO!
Moerig is offline  
Reply With Quote
Old 06-30-2011, 04:12 AM
  #987
Top_Gunn
 
Join Date: Jun 2005
Location: Granger, IN
Posts: 1,653
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: roger.alli

Just to keep the post count up.

http://www.youtube.com/embed/2eYoymfSqN0''

These guy know aerodynamics.

Pay no attention to these Australian people. Down there, since they're upside down, the planes have the curved surface on the bottom of the wing instead of the top. A flight instructor I trust told me this, and besides, that's how it seems to me, so scr*w the physics.
Top_Gunn is offline  
Reply With Quote
Old 06-30-2011, 04:38 AM
  #988
Selleri
 
Selleri's Avatar
 
Join Date: Jan 2003
Location: Keflavik, ICELAND
Posts: 1,116
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse

I posted months ago about having actually done 3 consecutive 360's into and out of a 100+ knot wind (well over 200 kts cumulative groundspeed difference) in a 320,000 lb airplane that was within 30 kts of stall speed for those conditions. Once established in the turn, with a million $$ worth of auto pilot doing the flying so I could stay kicked back and relaxed.....

Nothing. No trim changes, no throttle changes, NO AIRSPEED CHANGES......nothing. Why? Cus what I said in post #1 is absolutely true. An airborne aircraft is completely unaffected and doesn't give s sh^t where the (steady state) wind is from. PERIOD. If that weren't the case then I'd have been 170kts below stall speed when downwind and would not be alive to type here in this thread.

What else is there to talk about?
Futaba vs JR...
Selleri is offline  
Reply With Quote
Old 06-30-2011, 08:38 AM
  #989
Cosmicwind
 
Join Date: Aug 2003
Location: Hamburg, NY
Posts: 41
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

While I agree that airspeed is certainly different than ground speed, I disagree that wind has no effect when turning upwind or downwind. The aircraft has mass (weight) and needs time to accelerate or slow down (relative to ground speed) to maintain the same airspeed. Take a relatively heavy (scale ship) plane, fly it upwind on windy day, make a relatively quick 180º turn to downwind and watch what happens. The plane will drop because it cannot accelerate fast enough (due to its mass) to maintain the same airspeed when turning downwind. That is why experienced pilots will add some throttle as they begin their downwind turn.

Dave S.

(yes the plane will fly from the moving treadmill )

Cosmicwind is offline  
Reply With Quote
Old 06-30-2011, 09:04 AM
  #990
Top_Gunn
 
Join Date: Jun 2005
Location: Granger, IN
Posts: 1,653
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
The aircraft has mass (weight) and needs time to accelerate or slow down (relative to ground speed) to maintain the same airspeed.
What does "accelerate or slow down (relative to ground speed)" mean? When it turns downwind, its ground speed will indeed increase. That occurs not because the wind is "pushing" the plane or some such nonsense, but because the plane is flying in a moving mass of air, which always, no matter what the plane is doing, adds its (the air's) speed relative to the ground to what would be the plane's calm-air groundspeed. But that change in groundspeed has nothing to do with its airspeed. The airplane's ground speed affects where it is relative to the ground. It cannot affect the way it flies, as except for gravity the ground exerts no forces on the plane. You could think about somebody in a hot-air balloon flying an RC plane in a circle around the balloon in a steady wind. If you want to think. Many people don't. Theory, all the books, all the experience of pilots show that this downwind turn stuff is indeed a myth. But you don't have to agree with it, just as you don't have to agree that the earth is in orbit around the sun. (Hey, it looks to me like the sun goes around the earth. Look into a telescope?? Hey, I don't need no stinkin' evidence.)

It's probably time for another post saying that gusts affect airspeed so the "myth" proponents are full of it. 15 to go!
Top_Gunn is offline  
Reply With Quote
Old 06-30-2011, 09:11 AM
  #991
rcjets_63
 
rcjets_63's Avatar
 
Join Date: Feb 2008
Location: Tempe, AZ
Posts: 2,580
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Post Count - 986

Red Leader: Almost there, almost there
Attached Thumbnails
Click image for larger version

Name:	Ig11619.jpg
Views:	21
Size:	11.0 KB
ID:	1629740  
rcjets_63 is offline  
Reply With Quote
Old 06-30-2011, 10:52 AM
  #992
Moerig
 
Join Date: May 2008
Location: , NAMIBIA
Posts: 303
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: Selleri


Quote:
ORIGINAL: highhorse

I posted months ago about having actually done 3 consecutive 360's into and out of a 100+ knot wind (well over 200 kts cumulative groundspeed difference) in a 320,000 lb airplane that was within 30 kts of stall speed for those conditions. Once established in the turn, with a million $$ worth of auto pilot doing the flying so I could stay kicked back and relaxed.....

Nothing. No trim changes, no throttle changes, NO AIRSPEED CHANGES......nothing. Why? Cus what I said in post #1 is absolutely true. An airborne aircraft is completely unaffected and doesn't give s sh^t where the (steady state) wind is from. PERIOD. If that weren't the case then I'd have been 170kts below stall speed when downwind and would not be alive to type here in this thread.

What else is there to talk about?
Futaba vs JR...
Valid point, when turning downwind will DSMX be at a disadvantage to FASST. With more antennas, Spek could take more time to accelerate to the downwind velocity intererence waveform.
Moerig is offline  
Reply With Quote
Old 06-30-2011, 11:20 AM
  #993
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: Cosmicwind

While I agree that airspeed is certainly different than ground speed, I disagree that wind has no effect when turning upwind or downwind. The aircraft has mass (weight) and needs time to accelerate or slow down (relative to ground speed) to maintain the same airspeed. Take a relatively heavy (scale ship) plane, fly it upwind on windy day, make a relatively quick 180º turn to downwind and watch what happens. The plane will drop because it cannot accelerate fast enough (due to its mass) to maintain the same airspeed when turning downwind. That is why experienced pilots will add some throttle as they begin their downwind turn.

Dave S.

(yes the plane will fly from the moving treadmill )

Oh for crying out loud, read the thread. See that this notion has been beaten to death and corrected a dozen or more times at least.
highhorse is offline  
Reply With Quote
Old 06-30-2011, 11:27 AM
  #994
highhorse
Thread Starter
 
highhorse's Avatar
 
Join Date: Nov 2006
Location: Memphis, TN
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse


Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
I dont get that one, never seen a pelican do it so it cannot be safe....also turning in/out of a jetstream is not a steady state condition. Once in it it may be. For safety we always fly into a jetstream, it does slow you down a bit but at least you dont have to turn downwind.And dont try this in a simulator, its not the same either. Real planes use airmolecules, FS uses electrons which can turn a lot easier and travel faster.
I'm gonna give u the benefit of the doubt and assume ur kidding? It's getting pretty hard to tell...........
Ok, I am kidding about the pelicans...

JUST 20 POSTS TO GO!
Too bad u were only kidding about the pelicans, cus most of what u posted was bunk. Read the thread for hundreds of explanations why.

And because you refuse to understand what should have been an obvious point, I will clarify; The 360's were all conducted within the stream. The jetstream is no some tube of air on can enter and exit within the span of a 360 turn. Go make your living in it for 26 years and then come back and tell us we the "we" is in the highlighted sentence.
highhorse is offline  
Reply With Quote
Old 06-30-2011, 12:19 PM
  #995
BalsaBrkr
 
Join Date: Apr 2006
Location: Ashland, MA
Posts: 63
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse


Quote:
ORIGINAL: Cosmicwind

While I agree that airspeed is certainly different than ground speed, I disagree that wind has no effect when turning upwind or downwind. The aircraft has mass (weight) and needs time to accelerate or slow down (relative to ground speed) to maintain the same airspeed. Take a relatively heavy (scale ship) plane, fly it upwind on windy day, make a relatively quick 180º turn to downwind and watch what happens. The plane will drop because it cannot accelerate fast enough (due to its mass) to maintain the same airspeed when turning downwind. That is why experienced pilots will add some throttle as they begin their downwind turn.

Dave S.

(yes the plane will fly from the moving treadmill )

Oh for crying out loud, read the thread. See that this notion has been beaten to death and corrected a dozen or more times at least.
Indeed, the plane most certainly will not take off from the moving treadmill
BalsaBrkr is offline  
Reply With Quote
Old 06-30-2011, 12:22 PM
  #996
BalsaBrkr
 
Join Date: Apr 2006
Location: Ashland, MA
Posts: 63
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse
The jetstream is no some tube of air on can enter and exit within the span of a 360 turn.
I'd like to tap your vast experience, how many degrees does it require?
BalsaBrkr is offline  
Reply With Quote
Old 06-30-2011, 12:22 PM
  #997
Moerig
 
Join Date: May 2008
Location: , NAMIBIA
Posts: 303
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: highhorse

Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse


Quote:
ORIGINAL: Moerig


Quote:
ORIGINAL: highhorse

Exactly. I was turning into and out of a 100kt+ jetstream and I didn't die.

Go figure.
I dont get that one, never seen a pelican do it so it cannot be safe....also turning in/out of a jetstream is not a steady state condition. Once in it it may be. For safety we always fly into a jetstream, it does slow you down a bit but at least you dont have to turn downwind.And dont try this in a simulator, its not the same either. Real planes use airmolecules, FS uses electrons which can turn a lot easier and travel faster.
I'm gonna give u the benefit of the doubt and assume ur kidding? It's getting pretty hard to tell...........
Ok, I am kidding about the pelicans...

JUST 20 POSTS TO GO!
Too bad u were only kidding about the pelicans, cus most of what u posted was bunk. Read the thread for hundreds of explanations why.

And because you refuse to understand what should have been an obvious point, I will clarify; The 360's were all conducted within the stream. The jetstream is no some tube of air on can enter and exit within the span of a 360 turn. Go make your living in it for 26 years and then come back and tell us we the ''we'' is in the highlighted sentence.
Ok I was not only kidding about the pelicans, relax you are 100% correct since post 1, cant believe its still going, hence my attempts at some irony. I am messing with the idiots that come up with the most ridiculous schemes, like you said. Thought you would get it... I mean geez electrons vs air molecules.
Anyway I know nothing about jetstreams. I am assuming the transition is not an abrupt one but steady/progressive. I would assume such a stream is pretty wide as well.
Moerig is offline  
Reply With Quote
Old 06-30-2011, 12:38 PM
  #998
ceecrb1
 
ceecrb1's Avatar
 
Join Date: May 2008
Location: Valencia, SPAIN
Posts: 534
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

.
Attached Thumbnails
Click image for larger version

Name:	If10461.jpg
Views:	23
Size:	81.7 KB
ID:	1629825  
ceecrb1 is offline  
Reply With Quote
Old 06-30-2011, 12:44 PM
  #999
BalsaBrkr
 
Join Date: Apr 2006
Location: Ashland, MA
Posts: 63
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
ORIGINAL: ceecrb1
Flying dogs
If you examine the dogs shape they are clearly torpedoes and therefore better understood using the laws of hydrodynamics than aerodynamics – so it should be clear they don’t need lift, only buoyancy – which of course removes all risk from the downwind turn
BalsaBrkr is offline  
Reply With Quote
Old 06-30-2011, 12:48 PM
  #1000
ceecrb1
 
ceecrb1's Avatar
 
Join Date: May 2008
Location: Valencia, SPAIN
Posts: 534
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Aaah so thats why superman doesnt have this problem either?
ceecrb1 is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 11:12 PM.