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

Downwind turn Myth

Reply
Old 06-30-2011, 03:21 PM
  #1026
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: rjbob

Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

Again you are referencing the ground. If you used exactly the same inputs the aircraft would react the same, no closer to stall, only the turn would be elongated in the direction of the wind.
So if I understand you correctly, in my example below, if I used the same inputs for turn two, the bottom senario is roughly what the turn should look like?

You're kind of getting the idea...but the 2nd illustration would take the shape of a parallelogram. All the airspeeds in the 2nd illustration, however, would match the airspeeds in the 1st illustration.

In order to make the ground track in the 2nd illustration match the first, the 2nd illustration would include 2 turns of more than 90 degrees and 2 turns of less than 90 degrees...which could easily be accomplished with the same bank angles and airspeeds.
Ok, lets look at one turn at a time. If I gave the inputs needed to force the ground track in the bottom example to be the same as the top example for turn two, what would happen to my airspeed?
No wind situation...heading 360 degrees/course 360 degrees...left turn/30 degrees of bank...hold bank until course is 270 degrees and level out Since there is wind, the heading is the same as the course. During the turn, the airspeed drops, maybe 2 knots due to the slightly higher wing loading. Again...this is in NO WIND.

Now let's take a headwind...Again the heading and the course starts at 360 degrees and the airspeed is the same as in the no wind situation. A Left turn/30 degrees of bank. The bank angle is again held to 30 degrees until the COURSE is 270 degrees then level out. The heading is now, say, 285 degrees but the course and all airspeeds and ground track are identical. as in the no wind situation. And the control inputs are also identical. The pilot is responsible for stopping the turn when the desired course is attained.
rjbob is offline  
Reply With Quote
Old 06-30-2011, 03:32 PM
  #1027
cfircav8r
 
cfircav8r's Avatar
 
Join Date: Jul 2004
Location: Hampton, IA
Posts: 1,237
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: rjbob


Quote:
ORIGINAL: flythesky


Quote:
ORIGINAL: Top_Gunn


Quote:
ORIGINAL: flythesky

A plane will lose airspeed in a turn because of the increased drag from the deflected control surfaces. It will lose more in a downwind turn than an upwind turn because of the increased deflection of the control surfaces associated with downwind turns.
Am I right in thinking that by ''downwind turn'' you mean the turn from the downwind leg to the base leg (or to final, if you make a 180 degree turn)? If so, it's true, but this thread seems to be mostly about people thinking that turning toward downwind loses you more speed than other turns, even if the control inputs are the same. That one's the myth.
You are correct. One problem with the thread was that there was never a definition of what a downwind turn was. A 90deg turn or a 180 deg turn or where in the circuit it was.

The bottom line, though, is that no matter what one's definition of a downwind turn (upwind to downwind or downwind to upwind), it is a still myth. Either way, the plane flies the same.

Ok, for clarification, what I and most people I know refer to as a downwind turn is represented by turn two in my example. Now, with that defined, what would happen to my airspeed in turn two if I forced the aircraft in the bottom example to have the same ground track as the top example?
If you look at my example in post 1020 you will see turn two requires a greater than 90 degree turn. This can be done one of two ways.
1. you can do a standard turn and hold it longer
2. you can increase bank angle to keep the time the same, this will cause you to loose even more airspeed due to the higher wing loading not the wind or inertia or any other erroneous reason.
cfircav8r is offline  
Reply With Quote
Old 06-30-2011, 03:33 PM
  #1028
hugger-4641
 
hugger-4641's Avatar
 
Join Date: Oct 2008
Location: McKenzie, TN
Posts: 1,875
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: cfircav8r

Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

Again you are referencing the ground. If you used exactly the same inputs the aircraft would react the same, no closer to stall, only the turn would be elongated in the direction of the wind.
So if I understand you correctly, in my example below, if I used the same inputs for turn two, the bottom senario is roughly what the turn should look like?

If you make a normal 90 deg turn using the same bank angle and throttle settings and maintain altitude you will not stall but you will have a pattern that looks like this. While it looks like more than a 90 deg turn on the up wind turns and less than 90 on the down wind this is just your ground track, the actual headings will be true right angles.
Ok, for clarification of my question, ground track is all that an Rc pilot is concerned with. So I still don't have an answer. I'll ask again: If I force the ground track to look identical in my two examples below, what will happen to my airspeed in turn two of the bottom example as compared to the top?


Attached Thumbnails
Click image for larger version

Name:	Mk25535.jpg
Views:	13
Size:	61.8 KB
ID:	1629896  
hugger-4641 is offline  
Reply With Quote
Old 06-30-2011, 03:38 PM
  #1029
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

Again you are referencing the ground. If you used exactly the same inputs the aircraft would react the same, no closer to stall, only the turn would be elongated in the direction of the wind.
So if I understand you correctly, in my example below, if I used the same inputs for turn two, the bottom senario is roughly what the turn should look like?

If you make a normal 90 deg turn using the same bank angle and throttle settings and maintain altitude you will not stall but you will have a pattern that looks like this. While it looks like more than a 90 deg turn on the up wind turns and less than 90 on the down wind this is just your ground track, the actual headings will be true right angles.
Ok, for clarification of my question, ground track is all that an Rc pilot is concerned with. So I still don't have an answer. I'll ask again: If I force the ground track to look identical in my two examples below, what will happen to my airspeed in turn two of the bottom example as compared to the top?


Again...you can use the EXACT SAME BANK ANGLES and the airpeeds will be identical. You merely hold the turn for a longer or a shorter time to maintain the ground track you desire.

Can't wait for dinner.
rjbob is offline  
Reply With Quote
Old 06-30-2011, 03:41 PM
  #1030
hugger-4641
 
hugger-4641's Avatar
 
Join Date: Oct 2008
Location: McKenzie, TN
Posts: 1,875
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: cfircav8r


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: rjbob


Quote:
ORIGINAL: flythesky


Quote:
ORIGINAL: Top_Gunn


Quote:
ORIGINAL: flythesky

A plane will lose airspeed in a turn because of the increased drag from the deflected control surfaces. It will lose more in a downwind turn than an upwind turn because of the increased deflection of the control surfaces associated with downwind turns.
Am I right in thinking that by ''downwind turn'' you mean the turn from the downwind leg to the base leg (or to final, if you make a 180 degree turn)? If so, it's true, but this thread seems to be mostly about people thinking that turning toward downwind loses you more speed than other turns, even if the control inputs are the same. That one's the myth.
You are correct. One problem with the thread was that there was never a definition of what a downwind turn was. A 90deg turn or a 180 deg turn or where in the circuit it was.

The bottom line, though, is that no matter what one's definition of a downwind turn (upwind to downwind or downwind to upwind), it is a still myth. Either way, the plane flies the same.

Ok, for clarification, what I and most people I know refer to as a downwind turn is represented by turn two in my example. Now, with that defined, what would happen to my airspeed in turn twoif I forced the aircraft in the bottom example to have the same ground track as thetopexample?
If you look at my example in post 1020 you will see turn two requires a greater than 90 degree turn. This can be done one of two ways.
1. you can do a standard turn and hold it longer
2. you can increase bank angle to keep the time the same, this will cause you to loose even more airspeed due to the higher wing loading not the wind or inertia or any other erroneous reason.
Bingo! this is what I am saying happens to an Rc pilot when he makes a turn downwind, this is what I am saying is not a "myth".
hugger-4641 is offline  
Reply With Quote
Old 06-30-2011, 03:47 PM
  #1031
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: rjbob


Quote:
ORIGINAL: flythesky


Quote:
ORIGINAL: Top_Gunn


Quote:
ORIGINAL: flythesky

A plane will lose airspeed in a turn because of the increased drag from the deflected control surfaces. It will lose more in a downwind turn than an upwind turn because of the increased deflection of the control surfaces associated with downwind turns.
Am I right in thinking that by ''downwind turn'' you mean the turn from the downwind leg to the base leg (or to final, if you make a 180 degree turn)? If so, it's true, but this thread seems to be mostly about people thinking that turning toward downwind loses you more speed than other turns, even if the control inputs are the same. That one's the myth.
You are correct. One problem with the thread was that there was never a definition of what a downwind turn was. A 90deg turn or a 180 deg turn or where in the circuit it was.

The bottom line, though, is that no matter what one's definition of a downwind turn (upwind to downwind or downwind to upwind), it is a still myth. Either way, the plane flies the same.

Ok, for clarification, what I and most people I know refer to as a downwind turn is represented by turn two in my example. Now, with that defined, what would happen to my airspeed in turn two if I forced the aircraft in the bottom example to have the same ground track as the top example?
If you look at my example in post 1020 you will see turn two requires a greater than 90 degree turn. This can be done one of two ways.
1. you can do a standard turn and hold it longer
2. you can increase bank angle to keep the time the same, this will cause you to loose even more airspeed due to the higher wing loading not the wind or inertia or any other erroneous reason.
Bingo! this is what I am saying happens to an Rc pilot when he makes a turn downwind, this is what I am saying is not a ''myth''.
Did you not read the part about holding the turn longer? You're maintaining that you can't accomplish your objective with the same control inputs. When someone tells you how to do it, you ignore it.
rjbob is offline  
Reply With Quote
Old 06-30-2011, 03:51 PM
  #1032
cfircav8r
 
cfircav8r's Avatar
 
Join Date: Jul 2004
Location: Hampton, IA
Posts: 1,237
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Again the myth is that the wind is pushing you not that pilots have trouble. Many pilots believe they are having trouble because the wind is "pushing on the plane." That is the argument. Many phases of flight confuse R/C pilots. When you are flying towards yourself the rudder and ailerons appear to act in reverse and you need to know the reason why when you move the stick right it rolls left. This argument would be akin to saying the actual controls reverse, not just our perception of it.
cfircav8r is offline  
Reply With Quote
Old 06-30-2011, 04:01 PM
  #1033
hugger-4641
 
hugger-4641's Avatar
 
Join Date: Oct 2008
Location: McKenzie, TN
Posts: 1,875
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Did you not read the part about holding the turn longer? You're maintaining that you can't accomplish your objective with the same control inputs. When someone tells you how to do it, you ignore it.
cfircav8r
_____________________________

I didn't ignore anything, but yes, this is what I am saying. However, I think we are still not talking about the same objective. I can't hold the turn longer and maintain the EXACT same ground track, I have to complete the turn in the exact radius and ground track as I did in the "no wind" example. If you explained how todo this without losing airspeed or without adjusting control inputs, thenI definitely missed it.
hugger-4641 is offline  
Reply With Quote
Old 06-30-2011, 04:05 PM
  #1034
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: cfircav8r

Again the myth is that the wind is pushing you not that pilots have trouble. Many pilots believe they are having trouble because the wind is ''pushing on the plane.'' That is the argumant. Many phases of flight confuse R/C pilots. When you are flying towards yourself the rudder and ailerons appear to act in reverse and you need to know the reason why when you move the stick right it rolls left. This argument would be akin to saying the actual controls reverse, not just our perception of it.
These guys have a misconception. Instead of following through with the reasoning, they get to a certain point in the thought process and STOP.

And then they make up falsehoods in order to substantiate their mistaken views such as, "An experienced pilot will...etc, etc, etc."

Exasperating,
rjbob is offline  
Reply With Quote
Old 06-30-2011, 04:09 PM
  #1035
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Quote:
ORIGINAL: hugger-4641

Did you not read the part about holding the turn longer? You're maintaining that you can't accomplish your objective with the same control inputs. When someone tells you how to do it, you ignore it.
cfircav8r
_____________________________

I didn't ignore anything, but yes, this is what I am saying. However, I think we are still not talking about the same objective. I can't hold the turn longer and maintain the EXACT same ground track, I have to complete the turn in the exact radius and ground track as I did in the ''no wind'' example. If you explained how to do this without losing airspeed or without adjusting control inputs, then I definitely missed it.
You hold the turn longer or shorter in order to maintain the same radius.

I can do it and you can, too.

Because you are unable to visualize it doesn't mean others can't.
rjbob is offline  
Reply With Quote
Old 06-30-2011, 04:21 PM
  #1036
hugger-4641
 
hugger-4641's Avatar
 
Join Date: Oct 2008
Location: McKenzie, TN
Posts: 1,875
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: rjbob

Quote:
ORIGINAL: hugger-4641

Did you not read the part about holding the turn longer? You're maintaining that you can't accomplish your objective with the same control inputs. When someone tells you how to do it, you ignore it.
cfircav8r
_____________________________

I didn't ignore anything, but yes, this is what I am saying. However, I think we are still not talking about the same objective. I can't hold the turn longer and maintain the EXACT same ground track, I have to complete the turn in the exact radius and ground track as I did in the ''no wind'' example. If you explained how todo this without losing airspeed or without adjusting control inputs, thenI definitely missed it.
You hold the turn longer or shorter in order to maintain the same radius.

I can do it and you can, too.

Because you are unable to visualize it doesn't mean others can't.
Then I must be confused about what you mean by "holding the turn longer" . I am assuming you mean either starting the turn sooner, or maintaining it for a longer time. If so then you are correct, I can not visualizehow you can do this and still follow the same ground track, orwithout affecting airspeed.
hugger-4641 is offline  
Reply With Quote
Old 06-30-2011, 04:58 PM
  #1037
cfircav8r
 
cfircav8r's Avatar
 
Join Date: Jul 2004
Location: Hampton, IA
Posts: 1,237
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

You are right to make it look the same YOU will loose airspeed due to the higher G load. It is not the wind causing it it is your desire to MAKE the turn look a certain way. Part of being a good pilot is knowing your planes, and your own, limitations. If, in your desire to make your ground track look perfect, you stall/crash you have nothing and no one to blame but yourself. Not the wind, not inertia, not gremlins.
cfircav8r is offline  
Reply With Quote
Old 06-30-2011, 05:09 PM
  #1038
acerc
 
acerc's Avatar
 
Join Date: Sep 2006
Location: The Sunshine state, when it's not raining!
Posts: 8,108
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Just read this thread out of boredom and all I can add is           OMG-really.
acerc is offline  
Reply With Quote
Old 06-30-2011, 05:20 PM
  #1039
hugger-4641
 
hugger-4641's Avatar
 
Join Date: Oct 2008
Location: McKenzie, TN
Posts: 1,875
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: cfircav8r

You are right to make it look the same YOU will loose airspeed due to the higher G load. It is not the wind causing it it is your desire to MAKE the turn look a certain way. Part of being a good pilot is knowing your planes, and your own, limitations. If, in your desire to make your ground track look perfect, you stall/crash you have nothing and no one to blame but yourself. Not the wind, not inertia, not gremlins.
Finally, we get all theposturing andcondecention out of the way and get down to the point! Different perceptions of the same facts! Yes, I totaly understand that for a pilot who does not care about his ground track, a turn down wind is no different than any other. But, for a pilot who is concerned with nothing else but his ground track, crashing in a down wind turn is not a myth!

Thanks for helping me articulate whatI have been struggling with. If this does notclear it up for everyone else who has berated and belittled those who didn't percieve the argument the same way, then my Cub is waiting and theoffer for dinner still stands.cfircav8r,should you ever make it down my way, your dinner is waiting for having patience with me thru this discussion instead of trying to bully me into submission !
hugger-4641 is offline  
Reply With Quote
Old 06-30-2011, 05:24 PM
  #1040
flythesky
 
Join Date: Dec 2002
Location: Los Angeles, CA
Posts: 151
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: cactusflyer


Quote:
ORIGINAL: flythesky

A plane will lose airspeed in a turn because of the increased drag from the deflected control surfaces. It will lose more in a downwind turn than an upwind turn because of the increased deflection of the control surfaces associated with downwind turns.
WRONG!

Tailwinds,

John
Such a reasoned and well thought out response.

flythesky is offline  
Reply With Quote
Old 06-30-2011, 05:26 PM
  #1041
Cosmicwind
 
Join Date: Aug 2003
Location: Hamburg, NY
Posts: 41
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

RJBob,
I apologize for my poorly worded post. I did not mean to imply anything about anyone's flying ability. I was simply trying to convey my thoughts.

Regards,
Dave S.

Cosmicwind is offline  
Reply With Quote
Old 06-30-2011, 05:37 PM
  #1042
flythesky
 
Join Date: Dec 2002
Location: Los Angeles, CA
Posts: 151
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: flythesky


Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

Again you are referencing the ground. If you used exactly the same inputs the aircraft would react the same, no closer to stall, only the turn would be elongated in the direction of the wind.
So if I understand you correctly, in my example below, if I used the same inputs for turn two, the bottom senario is roughly what the turn should look like?

No. All turn would look alike but the control movements would be different for each turn.


You didn't read my question thoroughly, I said if I used the same inputs, meaningI usethe exact same stick movement which would equate to exact same elevator, rudder, and aileron deflection. If I do this ,the bottom track in my example should resemble what would happen in turn two.
Sorry. Turns one and two would be similar. in shape. Turns three and four would be elongated (streched) in the direction of the wind.

flythesky is offline  
Reply With Quote
Old 06-30-2011, 06:23 PM
  #1043
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: Cosmicwind

RJBob,
I apologize for my poorly worded post. I did not mean to imply anything about anyone's flying ability. I was simply trying to convey my thoughts.

Regards,
Dave S.

What is really difficult is the fact that we're in a forum setting. It's impossible to take you up in a plane or demonstrate something at the flying field...or even wave my hands to simulate a flying plane over a cup of coffee.

There would be no arguments whatsoever in re this topic if the myth believers went for a ride with a professional pilot or watched and listened while a competent R/C pilot demonstrated some good old fashioned myth-busting.

Again...Happy flying!

Bob
rjbob is offline  
Reply With Quote
Old 06-30-2011, 06:43 PM
  #1044
pflynn73
 
Join Date: Mar 2008
Location: Boulder City, NV
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Thanks Highhorse for teaching me something very valuable. What is the next lesson? Thanks again Highhorse!
pflynn73 is offline  
Reply With Quote
Old 06-30-2011, 08:38 PM
  #1045
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: hugger-4641


Quote:
ORIGINAL: cfircav8r

You are right to make it look the same YOU will loose airspeed due to the higher G load. It is not the wind causing it it is your desire to MAKE the turn look a certain way. Part of being a good pilot is knowing your planes, and your own, limitations. If, in your desire to make your ground track look perfect, you stall/crash you have nothing and no one to blame but yourself. Not the wind, not inertia, not gremlins.
Finally, we get all the posturing and condecention out of the way and get down to the point! Different perceptions of the same facts! Yes, I totaly understand that for a pilot who does not care about his ground track, a turn down wind is no different than any other. But, for a pilot who is concerned with nothing else but his ground track, crashing in a down wind turn is not a myth!

Thanks for helping me articulate what I have been struggling with. If this does not clear it up for everyone else who has berated and belittled those who didn't percieve the argument the same way , then my Cub is waiting and the offer for dinner still stands. cfircav8r, should you ever make it down my way, your dinner is waiting for having patience with me thru this discussion instead of trying to bully me into submission ![img][/img]
Did anyone ever say "crashing in a downwind turn is a myth"??? NO, THATS NOT THE MYTH. The "myth" refers to the ERRONEOUS REASONS people posit for their downwind crashes. It's important because the myth IS a myth, and leads people to make the wrong (or at least not the best) compensation for the very real problem of downwind crashes.

Is ANYONE really that concerned with ground track being exactly the same as in dead calm? Even in competition/pattern flying, when you have to maintain ground track by crabbing into the wind, do the judges really take points off for having a longer radius on the downwind turns? I've never flown patterns, but that seems awfully hard to see or judge anyway. Furthermore, in your original dinner challenge, did you specify that the ground track and turn radii remain the same as in dead calm? I don't think so. You are now re-framing your challenge and your argument because you now know your original concept was somewhat in error. You might benefit from accepting that, and I'm calling you on it (not belittling you).

The problem is not so much that pilots try to maintain a "perfect" rectangular ground track, but that they try to maintain steady ground SPEED. If you try to keep your visually apparent speed (ground speed) looking the same as on a calm day, then yes, you will definitely lose airspeed on the "downwind" turn and gain airspeed going upwind. That is bad and that's no myth.

If you expect and allow the plane to have different ground speeds upwind vs. downwind, then you usually stay out of trouble. If you allow for this different visual ground speed appearance in the different directions of flight, then even if you DO try to maintain ground track by constantly crabbing into the wind, I doubt the loss in airspeed caused by the longer (greater than 90 degree) turn would be very significant. The point of this thread is that you should not attempt to do this at the same radius as upwind anyway. THAT IS THE LESSON, not "add throttle". If you keep your stick movements gradual and similar to what you do on a calm day, and let the downwind turn "elongate" and let the plane appear to accelerate in the down wind direction, YOU WILL NOT LOSE AIRSPEED ANY MORE THAN YOU DO ON YOUR UPWIND TURNS... and you will not crash. No throttle needed.

You may consider this a trivial or semantic point, but it's important. Most airspeed loss from turning downwind is NOT due to the trivial fact that such turns may be more than 90 degrees. Most of the airspeed loss is due to the pilot MAKING the plane lose airspeed by being unaware of the invisible wind speed, underestimating wind affect on ground track and ground speed, and by FORCING the plane to make turns that look the same downwind as upwind. In short, pilot mistakes ground speed for airspeed. Pilot error, NOT AERODYNAMICS. "Add throttle" is not the correct cure for this error.
RZielin is offline  
Reply With Quote
Old 06-30-2011, 08:46 PM
  #1046
rjbob
 
rjbob's Avatar
 
Join Date: Feb 2003
Location: Anchorage, AK
Posts: 1,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth


Quote:
ORIGINAL: RZielin

Quote:
ORIGINAL: hugger-4641


Quote:
ORIGINAL: cfircav8r

You are right to make it look the same YOU will loose airspeed due to the higher G load. It is not the wind causing it it is your desire to MAKE the turn look a certain way. Part of being a good pilot is knowing your planes, and your own, limitations. If, in your desire to make your ground track look perfect, you stall/crash you have nothing and no one to blame but yourself. Not the wind, not inertia, not gremlins.
Finally, we get all the posturing and condecention out of the way and get down to the point! Different perceptions of the same facts! Yes, I totaly understand that for a pilot who does not care about his ground track, a turn down wind is no different than any other. But, for a pilot who is concerned with nothing else but his ground track, crashing in a down wind turn is not a myth!

Thanks for helping me articulate what I have been struggling with. If this does not clear it up for everyone else who has berated and belittled those who didn't percieve the argument the same way , then my Cub is waiting and the offer for dinner still stands. cfircav8r, should you ever make it down my way, your dinner is waiting for having patience with me thru this discussion instead of trying to bully me into submission ![img][/img]
Did anyone ever say ''crashing in a downwind turn is a myth''??? NO, THATS NOT THE MYTH. The ''myth'' refers to the ERRONEOUS REASONS people posit for their downwind crashes. It's important because the myth IS a myth, and leads people to make the wrong (or at least not the best) compensation for the very real problem of downwind crashes.

Is ANYONE really that concerned with ground track being exactly the same as in dead calm? Even in competition/pattern flying, when you have to maintain ground track by crabbing into the wind, do the judges really take points off for having a longer radius on the downwind turns? I've never flown patterns, but that seems awfully hard to see or judge anyway. Furthermore, in your original dinner challenge, did you specify that the ground track and turn radii remain the same as in dead calm? I don't think so. You are now re-framing your challenge and your argument because you now know your original concept was somewhat in error. You might benefit from accepting that, and I'm calling you on it (not belittling you).

The problem is not so much that pilots try to maintain a ''perfect'' rectangular ground track, but that they try to maintain steady ground SPEED. If you try to keep your visually apparent speed (ground speed) looking the same as on a calm day, then yes, you will definitely lose airspeed on the ''downwind'' turn and gain airspeed going upwind. That is bad and that's no myth.

If you expect and allow the plane to have different ground speeds upwind vs. downwind, then you usually stay out of trouble. If you allow for this different visual ground speed appearance in the different directions of flight, then even if you DO try to maintain ground track by constantly crabbing into the wind, I doubt the loss in airspeed caused by the longer (greater than 90 degree) turn would be very significant. The point of this thread is that you should not attempt to do this at the same radius as upwind anyway. THAT IS THE LESSON, not ''add throttle''. If you keep your stick movements gradual and similar to what you do on a calm day, and let the downwind turn ''elongate'' and let the plane appear to accelerate in the down wind direction, YOU WILL NOT LOSE AIRSPEED ANY MORE THAN YOU DO ON YOUR UPWIND TURNS... and you will not crash. No throttle needed.

You may consider this a trivial or semantic point, but it's important. Most airspeed loss from turning downwind is NOT due to the trivial fact that such turns may be more than 90 degrees. Most of the airspeed loss is due to the pilot MAKING the plane lose airspeed by being unaware of the invisible wind direction, underestimating wind affect on ground track and ground speed, and by FORCING the plane to make turns that look the same downwind as upwind. In short, pilot mistakes ground speed for airspeed. Pilot error, NOT AERODYNAMICS. ''Add throttle'' is not the correct cure for this error.
There ya go!
rjbob is offline  
Reply With Quote
Old 06-30-2011, 11:46 PM
  #1047
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: hugger-4641


Quote:
ORIGINAL: cfircav8r

You are right to make it look the same YOU will loose airspeed due to the higher G load. It is not the wind causing it it is your desire to MAKE the turn look a certain way. Part of being a good pilot is knowing your planes, and your own, limitations. If, in your desire to make your ground track look perfect, you stall/crash you have nothing and no one to blame but yourself. Not the wind, not inertia, not gremlins.
Finally, we get all the posturing and condecention out of the way and get down to the point! Different perceptions of the same facts! Yes, I totaly understand that for a pilot who does not care about his ground track, a turn down wind is no different than any other. But, for a pilot who is concerned with nothing else but his ground track, crashing in a down wind turn is not a myth!

Thanks for helping me articulate what I have been struggling with. If this does not clear it up for everyone else who has berated and belittled those who didn't percieve the argument the same way , then my Cub is waiting and the offer for dinner still stands. cfircav8r, should you ever make it down my way, your dinner is waiting for having patience with me thru this discussion instead of trying to bully me into submission ![img][/img]
Yes you are right from that point of view, but the argument is about something else. The pilot obsessed with a ground track for whatever reason (aerobatic pattern being judged for example) would have to do a lot more work to maintain track. Many years ago when flying F3A and you were judged on wing level and ground track we did horrible turns with constant bank angle but with rudder co-ordinated to maintain the illusion of wind not affecting you. If you did not watch airspeed the downwind turn WOULD get you for sure (or loop whatever). many pilots managed this well without understanding the physics/aerodynamics involved hence the myth is born "the wind pushed the plane".
Wind does not affect airplanes ONLY pilots.
Hope we all agree now.
Moerig is offline  
Reply With Quote
Old 07-01-2011, 01:16 AM
  #1048
gene737
 
Join Date: Feb 2004
Location: Longview, TX
Posts: 36
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

If any of you are still struggling with this concept, perhaps a visit to the PROBRO site will help clear up any questions. Just ask and ye will receive.
gene737 is offline  
Reply With Quote
Old 07-01-2011, 07:51 AM
  #1049
Airplanes400
 
Airplanes400's Avatar
 
Join Date: Jun 2008
Location: Florida
Posts: 1,631
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

OMG ... this thread is a myth!
Airplanes400 is offline  
Reply With Quote
Old 07-01-2011, 08:00 AM
  #1050
Airplanes400
 
Airplanes400's Avatar
 
Join Date: Jun 2008
Location: Florida
Posts: 1,631
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Downwind turn Myth

Good job people ... over 1,000 posts about absolutely nothing. I'm going to get the last 10 minutes of my life back and do something more productive ... like watch Jerry Springer, or watch the show with 5 women sitting around a table talking nonsense about nonsense, or see what Kate Middleton is wearing while on tour in Canada with Prince William...
Airplanes400 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 03:46 AM.