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

Downwind turn Myth

Reply
Old 09-16-2015, 04:07 PM
  #1626
Propworn
 
Propworn's Avatar
 
Join Date: Jul 2002
Location: Canada
Posts: 1,554
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by hounddog View Post
u will never convince some people that the "down wind turn myth" is just that a "myth"
some people still believe in the easter bunny, tooth ferry, santa clause, the boggy man, to say nothing of the dwt myth. I suggest to just leave them to their devices they'll never be convinced.
hey why are you picking on sandy claws eh!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Propworn is offline  
Reply With Quote
Old 09-16-2015, 05:38 PM
  #1627
rutanman
 
Join Date: Aug 2002
Location: Altoona, PA
Posts: 30
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Real Airplanes - Pitot static tube to measure general "Air Velocity" over wing. Stall speed is stall speed for an airplane - if you're riding exactly stall speed and you encounter a steady tailwind - the plane has to make up the difference - usually a very shallow descent to regain the previous flying speed if the plane was at trimmed conditions. (If the plane wasn't trimmed - then all bets are off - you are not in a steady state condition.) A gust - say a quick breeze will send a plane into a phugoid motion. Can also be simulated by trimming the plane at a given power setting and deflecting the elevator and then placing it back to it's original position. If the plane is statically and dynamically stable - the planes oscillations will dampen out to it's original condition.

Don't confuse beginner pilots - Always take off and land into the wind. Shortens takeoff and landing and allows a pilot to clear obstacles around an airport.

And beginner r/c pilots- do so (takeoff into the wind) until you have a plane powerful enough to make the vector component of wind not important where your difference of power available to power required is great.

Wind is a force - a pressure per unit area. It has a magnitude and a direction and it must obey all laws of physics.

A plane loosely tied down could technically be flying if ground head winds would be above it's stall speed. An airspeed indicator, if powered up would show the speed of the wind as the plane's indicated airspeed.

(see pages 176,177 and especially page 178 https://books.google.com/books?id=8D...stream&f=false )
rutanman is offline  
Reply With Quote
Old 09-16-2015, 11:26 PM
  #1628
Turbotronic
 
Join Date: Aug 2009
Location: Cape Town, SOUTH AFRICA
Posts: 468
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I know I don't have to read any of the daft arguments here. But just seeing it in the forum shakes my over optimistic dream that homo sapiens average IQ is more than 100. Sadly I am proven wrong every time.
It is not the issue of the "myth", just the will full ignorance to accept any argument other than that presented by the ego that saddens me. Here it is harmless but in the real world it causes untold misery.
Turbotronic is offline  
Reply With Quote
Old 09-17-2015, 12:15 AM
  #1629
HarryC
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,537
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Turbotronic View Post
But just seeing it in the forum shakes my over optimistic dream that homo sapiens average IQ is more than 100. Sadly I am proven wrong every time.
Since average IQ is defined as 100, you want the average IQ to be higher than the average IQ? That's impossible!!!!!!!!!!!
HarryC is offline  
Reply With Quote
Old 09-17-2015, 12:27 AM
  #1630
Turbotronic
 
Join Date: Aug 2009
Location: Cape Town, SOUTH AFRICA
Posts: 468
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by HarryC View Post
Since average IQ is defined as 100, you want the average IQ to be higher than the average IQ? That's impossible!!!!!!!!!!!
Yea I know... I am hoping the scientists got the test distribution median wrong since 100 is real stupid. In fact below 120's should not be allowed to vote or have more than 2 children IMO.
Then again I have a PHD uncle with 145 IQ which is the daftest of them all...
Turbotronic is offline  
Reply With Quote
Old 09-17-2015, 02:05 AM
  #1631
Carsten Groen
 
Carsten Groen's Avatar
 
Join Date: Nov 2004
Location: Denmark
Posts: 1,654
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by RZielin View Post
This is the exact concept that I demonstrated in a 2 part video a while back. I consider this proof that the Myth is indeed not true. Some day I'll try to do it with a real plane but it will require the perfect conditions and a bunch of time. I've posted this before, so forgive me if for that, but I hope this helps some of the newer arrivals to this thread who are just getting the idea of the frame of reference issue that drives this entire debate. Here's the link:

https://www.youtube.com/watch?v=PaPKLUdbqLU
Great videos, if these can't turn the minds of the "myth believers", nothing can
Carsten Groen is offline  
Reply With Quote
Old 09-17-2015, 03:52 AM
  #1632
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Turbotronic View Post
I know I don't have to read any of the daft arguments here. But just seeing it in the forum shakes my over optimistic dream that homo sapiens average IQ is more than 100. Sadly I am proven wrong every time.
It is not the issue of the "myth", just the will full ignorance to accept any argument other than that presented by the ego that saddens me. Here it is harmless but in the real world it causes untold misery.
Turbotronic; Myth NO.
Come on now Turbotronic; Being from the Southern Hemisphere even your Drains turn the wrong way ... Welcome To the Discussion. Glad to have ya.

Hey every one let's start any post with MYTH Yes or No
HoundDog is offline  
Reply With Quote
Old 09-17-2015, 08:08 AM
  #1633
BrightGarden
 
BrightGarden's Avatar
 
Join Date: Jun 2014
Location: Hudson Valley. New York. USA
Posts: 275
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

What would be great is every RC pilot get about 4-5 hours training in full scale aircraft.

By about this point of training you would get the concept of air versus ground tracking on that turn to base from downwind.

If there is 20 mph blowing right down the runway, to track square on the ground, you have to turn > 90 degrees to crab into the wind and get a square ground track.

This also gives an advantageous view of the runway.
BrightGarden is offline  
Reply With Quote
Old 09-17-2015, 12:21 PM
  #1634
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by BrightGarden View Post
What would be great is every RC pilot get about 4-5 hours training in full scale aircraft.

By about this point of training you would get the concept of air versus ground tracking on that turn to base from downwind.

If there is 20 mph blowing right down the runway, to track square on the ground, you have to turn > 90 degrees to crab into the wind and get a square ground track.

This also gives an advantageous view of the runway
.
The down wind turn Myth is just that a Myth
BrightGarden; said

"By about this point of training you would get the concept of air versus ground tracking on that turn to base from downwind".


Again U are speaking of Ground Track which is not the subject here it's about a constant rate turn from Up Wind `180 Degrees to Down wind Being Dangerous. Not Doe Wind to Base. It's on the other end of the runway.

It's only Dangerous When flying at a CAS and U increase your bank angle to an angle that has a greater Stall Speed than your CAS.

Last edited by HoundDog; 09-17-2015 at 12:26 PM.
HoundDog is offline  
Reply With Quote
Old 09-22-2015, 12:54 PM
  #1635
paladin
 
Join Date: Feb 2002
Location: Vestal, NY
Posts: 2,822
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

have a bridge for sale in Brooklyn if any of you are interested. even comes complete with toll booths.
paladin is offline  
Reply With Quote
Old 09-22-2015, 03:06 PM
  #1636
Rob2160
 
Rob2160's Avatar
 
Join Date: Jun 2010
Location: Sydney, AUSTRALIA
Posts: 4,786
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

It helps to understand the origin of the Downwind turn "myth"

The idea started when pilots were flying circuits on windy days when there was significant wind gradient between ground level and 1000ft agl.

Taking off and climbing upwind in 10 knots of headwind, then commencing a turn to downwind while also climbing into stronger winds (e.g 30kts tailwind at 1000ft) will definitely cause you to lose airspeed and approach the stall.

Instructors would say, "be careful turning downwind today as you will lose airspeed" and taking this caution out of context is how the myth was born.

It does not apply if you are turning in steady unchanging wind.
Rob2160 is offline  
Reply With Quote
Old 09-22-2015, 04:34 PM
  #1637
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Rob2160 View Post
It helps to understand the origin of the Downwind turn "myth"

The idea started when pilots were flying circuits on windy days when there was significant wind gradient between ground level and 1000ft agl.

Taking off and climbing upwind in 10 knots of headwind, then commencing a turn to downwind while also climbing into stronger winds (e.g 30kts tailwind at 1000ft) will definitely cause you to lose airspeed and approach the stall.

Instructors would say, "be careful turning downwind today as you will lose airspeed" and taking this caution out of context is how the myth was born.

It does not apply if you are turning in steady unchanging wind.'
Now that's the best explanation I've ever heard. Mystery Solved.
HoundDog is offline  
Reply With Quote
Old 09-23-2015, 03:43 AM
  #1638
Sport_Pilot
 
Sport_Pilot's Avatar
 
Join Date: Jan 2002
Location: Acworth, GA
Posts: 16,914
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Rob2160 View Post
It helps to understand the origin of the Downwind turn "myth"

The idea started when pilots were flying circuits on windy days when there was significant wind gradient between ground level and 1000ft agl.

Taking off and climbing upwind in 10 knots of headwind, then commencing a turn to downwind while also climbing into stronger winds (e.g 30kts tailwind at 1000ft) will definitely cause you to lose airspeed and approach the stall.

Instructors would say, "be careful turning downwind today as you will lose airspeed" and taking this caution out of context is how the myth was born.

It does not apply if you are turning in steady unchanging wind.
I understand it started when airspeed indicators were not used or with early inaccurate versions. Back then they had to judge by observing the ground speed only. The airspeed does not change when turning downwind.
Sport_Pilot is offline  
Reply With Quote
Old 09-23-2015, 08:37 AM
  #1639
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Sport_Pilot View Post
I understand it started when airspeed indicators were not used or with early inaccurate versions. Back then they had to judge by observing the ground speed only. The airspeed does not change when turning downwind .
airspeed does not change when turning downwind IN A CONSTANT VELOCITY WIND That is not higher than the stall speed for the bank angle of the turn. The plane, can not will, loose Air Speed if the relative wind is gusty or Wind Shear, let's say created by a Micro Burst or a sudden Gest front from an approaching Thunder Storm.

There are those on both sides of the issue that will never be convinced that what they believe is incorrect, they will go to their grave insisting that they are right ... Same thing with their Brand of R/C Radio system they have invested in or even the CHEVY or FORD they drive.
"It ain't over till it's Over" Well guess it's Over Yogi RIP.
HoundDog is offline  
Reply With Quote
Old 09-24-2015, 09:39 AM
  #1640
Lownverted
 
Lownverted's Avatar
 
Join Date: Aug 2002
Location: Palmdale, CA
Posts: 492
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

This guy looks like he was a victim of the downwind turn!

https://www.youtube.com/watch?v=zxbulrrQVig
Lownverted is offline  
Reply With Quote
Old 09-24-2015, 12:37 PM
  #1641
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Lownverted View Post
This guy looks like he was a victim of the downwind turn!

https://www.youtube.com/watch?v=zxbulrrQVig
"Bull Puckey" He released from the tow plane going UP wind Turned Down wind and lost altitude to gain speed. When he crashed he was turning INTO the Up wind Not WITH the down wind. His problem was too high stall Speed for the bank angle and the Air speed he had. Just another Dummy removed from the Gene Pool. Too bad for the sail plane though.
HoundDog is offline  
Reply With Quote
Old 09-24-2015, 01:00 PM
  #1642
dbsonic
 
dbsonic's Avatar
 
Join Date: Oct 2005
Location: san jose, CA
Posts: 816
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

That's a Swift aerobatic glider and he survived the crash. He was performing aerobatics on tow with a low ceiling. After doing a roll on tow and decided to release due to the excessive slack line(probably would have resulted in a rope break anyways). His mistake was deploying spoilers too soon in a low pattern and on a ship with a fairly high stall speed as compared to most gliders except perhaps a Fox. But yes, stalled it.
dbsonic is offline  
Reply With Quote
Old 09-24-2015, 01:17 PM
  #1643
HoundDog
 
HoundDog's Avatar
 
Join Date: Oct 2003
Location: Apache Junction AZ. WI 0WI8
Posts: 4,485
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by dbsonic View Post
That's a Swift aerobatic glider and he survived the crash. He was performing aerobatics on tow with a low ceiling. After doing a roll on tow and decided to release due to the excessive slack line(probably would have resulted in a rope break anyways). His mistake was deploying spoilers too soon in a low pattern and on a ship with a fairly high stall speed as compared to most gliders except perhaps a Fox. But yes, stalled it.
"S&*% Happens or as a deaf friend says POOP Occurs" Glad to hear he lived.
I would believe your reference to the "Down Wind Turn Myth" Was Tongue in Cheek.
Correct?
HoundDog is offline  
Reply With Quote
Old 09-24-2015, 01:36 PM
  #1644
dbsonic
 
dbsonic's Avatar
 
Join Date: Oct 2005
Location: san jose, CA
Posts: 816
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

That was the other poster, but yeah, I think he was being tongue in cheek.

In the full size forums there are similar discussions. Although more about questioning what might have happened in the most recent accident being reported. Unfortunately there are incidents every day in GA and often involve the landing phase.
dbsonic is offline  
Reply With Quote
Old 09-25-2015, 07:54 AM
  #1645
Turbotronic
 
Join Date: Aug 2009
Location: Cape Town, SOUTH AFRICA
Posts: 468
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

In software terms this thread is like an infinite loop. Arguments get repeated over and over. Get over it.
Try space-time vs speed of light as an argument with the flat earth society.
It has a better chance of agreement.
Turbotronic 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 08:06 AM.