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ORIGINAL: hugger-4641


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?

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ORIGINAL: hugger-4641



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?

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ORIGINAL: cfircav8r

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.

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ORIGINAL: hugger-4641


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?

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ORIGINAL: cfircav8r


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
<span style="color: #ff0000">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.
</span>

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ORIGINAL: hugger-4641


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''.

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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.

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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.

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ORIGINAL: rjbob

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.

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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.

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ORIGINAL: cactusflyer


WRONG!

Tailwinds,

John

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ORIGINAL: hugger-4641



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.

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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.

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ORIGINAL: hugger-4641


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]

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ORIGINAL: RZielin

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.

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ORIGINAL: hugger-4641


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]

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