Wind triangles?

Clip4 said:
Isn’t a course plotter a protractor and a ruler? Actually you can draw it on a chart using the compass rose of a VOR and the mileage scale on the sectional by simply changing courses and winds to magnetic.
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Is that the other way you mentioned here:
Clip4 said:
The diagram is one of two methods for drawing a wind triangle. ...but as an instructor you should be able to draw and explain a wind triangle using both methods.
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dtuuri said:
Is that the other way you mentioned here:
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Reading comprehension isn’t one of your strengths.

“The issue is there are no numeric values on the diagram, which is needed to draw it. The second diagram as portrayed is incorrect because the line A-B is KTAS not KIAS. YouTube has videos.” Speeds, distances and angles are numeric values. There are also 2 methods to draw a wind triangle.
 
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Clip4 said:
Reading comprehension isn’t one of your strengths.
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Hmm, seems like insults are one of yours. No problem, though, I just am trying to figure out the "other" method you refer to without showing it. Never too old to learn a new trick, you might say. The OP might be better served than me, if there really is another one that is.
Clip4 said:
“The issue is there are no numeric values on the diagram, which is needed to draw it. The second diagram as portrayed is incorrect because the line A-B is KTAS not KIAS. YouTube has videos.” Speeds, distances and angles are numeric values. There are also 2 methods to draw a wind triangle.
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dtuuri said:
This is why I think @Clip4 and @sarangan can't do what they say. The only way I know to draw a wind triangle is how I explained, at least if using just a protractor and ruler. To your point, though, the instant you can find your heading you can also find the groundspeed. Which one you measure first is up to you.

See figs 15 and 16: Path of Flight: Practical Information About Navigation of Private Aircraft
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I don't know what you mean by 'can't do what they say'. This is basic vector math. It becomes really simple when you write: Vg = Va + Vw where Vg = ground track vector, Va = Airplane velocity vector and Vw = wind vector.

From this vector sum, everything automatically falls out algebraically, including wind correction angle (angle between Vg and Va), and ground speed (length of the Vg vector).

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sarangan said:
I don't know what you mean by 'can't do what they say'. This is basic vector math. It becomes really simple when you write: Vg = Va + Vw where Vg = ground track vector, Va = Airplane velocity vector and Vw = wind vector.

From this vector sum, everything automatically falls out algebraically, including wind correction angle (angle between Vg and Va), and ground speed (length of the Vg vector).

View attachment 155536
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Using just a ruler and protractor on a chart, I couldn't see how you knew where to put the wind vector origin in order to place the vector at the head of the orange line. Most students probably wouldn't remember enough trig to do what you just drew, imo.
 
dtuuri said:
Using just a ruler and protractor on a chart, I couldn't see how you knew where to put the wind vector origin in order to place the vector at the head of the orange line. Most students probably wouldn't remember enough trig to do what you just drew, imo.
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With a ruler and protractor, draw your airplane velocity vector in an approximate direction, then from the head of that arrow, draw the wind vector. Then rotate the velocity vector around the departure point while keeping the wind vector's direction unchanged until the head of the wind arrow touches your desired track. That's the wind triangle. Alternatively, just let the math do the work.

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sarangan said:
With a ruler and protractor, draw your airplane velocity vector in an approximate direction, then from the head of that arrow, draw the wind vector. Then rotate the velocity vector around the departure point while keeping the wind vector's direction unchanged until the head of the wind arrow touches your desired track. That's the wind triangle. Alternatively, just let the math do the work.

View attachment 155543
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Now I understand what you did. It is why Path of Flight states (regarding your wind triangle), "In actual practice, we do not draw the triangle illustrated." So then, if this is the "other" way @Clip4 claims the OP needs to also be able to explain, I would disagree. Maybe he tried to explain yet a third way. :dunno: Going from true to magnetic as he said, and/or using the chart's own scale vs. a ruler, to me, is a distinction without a difference.
 
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It's basic high school trigonometry.

Dana,
who hasn't calculated a wind correction angle since 1977 but hasn't forgotten how.
 
dtuuri said:
Now I understand what you did. It is why Path of Flight states (regarding your wind triangle), "In actual practice, we do not draw the triangle illustrated." So then, if this is the "other" way @Clip4 claims the OP needs to also be able to explain, I would disagree. Maybe he tried to explain yet a third way. :dunno: Going from true to magnetic as he said, and/or using the chart's own scale vs. a ruler, to me, is a distinction without a difference.
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I'm not exactly following the above passage, but I don't think there is a "standard" way and an "alternate" way. Explanations may vary, but the underlying mathematics is the same.

The original question was about developing a deeper understanding of wind triangles. We can't really discuss triangles of any kind without getting into some mathematics. In practice, of course, nobody is really calculating wind correction angles anymore. Navigation by dead reckoning is a thing of the past.
 
sarangan said:
...I don't think there is a "standard" way and an "alternate" way.
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Me either, but @Clip4 said there was. There is only one way in actual practice according to the CAA and now the FAA: Draw the wind vector first from the departure point, not from the end of an articulating arm representing TAS.
sarangan said:
Explanations may vary, but the underlying mathematics is the same.
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The math is called simple arithmetic, not trigonometry, in Path of Flight (1946 ver.)
sarangan said:
In practice, of course, nobody is really calculating wind correction angles anymore.
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According to PHAK: "Either consciously or unconsciously, every good pilot thinks of the flight in terms of wind triangle." Which is why the OP wants to know more — he's preparing to teach it.
 
dtuuri said:
Me either, but @Clip4 said there was. There is only one way in actual practice according to the CAA and now the FAA: Draw the wind vector first from the departure point, not from the end of an articulating arm representing TAS.
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Drawing it one way you are representing A+B. The other way is saying B+A. A vector sum is commutative. There is no difference.
 
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sarangan said:
Drawing it one way you are representing A+B. The other way is saying B+A. A vector sum is commutative. There is no difference.
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Drawing a wind triangle the FAA's way is "the navigation way", no doubt because it's easier and more accurate. Your way has two pivot points as you swing the arcs. The FAA's way has only one pivot and can be done with a common plotter. So, imo, the OP should learn that way and teach that way rather than explain algebra and trig, which most student pilots don't have a grasp of.
 
dtuuri said:
Me either, but @Clip4 said there was. There is only one way in actual practice according to the CAA and now the FAA: Draw the wind vector first from the departure point, not from the end of an articulating arm representing TAS.

The math is called simple arithmetic, not trigonometry, in Path of Flight (1946 ver.)

According to PHAK: "Either consciously or unconsciously, every good pilot thinks of the flight in terms of wind triangle." Which is why the OP wants to know more — he's preparing to teach it.
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There are two different methods to draw the triangle.

 
Clip4 said:
There are two different methods to draw the triangle.

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Here's my take on that video. It's very nice as far as I watched, which was only enough to notice "Method A" is really one of several special navigation problems Path of Flight says are "based upon the wind vector diagram." So, there are even more ways than just two to draw a wind triangle if Method A is considered one of them. Such as, finding wind direction and velocity, finding the turning point toward an alternate airport, and finding the radius of action. The video makes it look like this is the same problem which can be solved in one of two ways, which it is not. In order to draw Method A, you need to first know the heading. Method B is used to "find" the heading before you even take off, which is why we use it to educate students, right?

That said, even the FAA first uses Method A, meaning a short sketch upwind of the desired course (shown by dotted lines), as a way to set the scene. Then they switch to a more practical application by drawing the other half of the rhombus to scale with measuring instruments to find the true heading. That is what they, imo, refer to as the "Wind Triangle".
 
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dtuuri said:
Here's my take on that video. It's very nice as far as I watched, which was only enough to notice "Method A" is really one of several special navigation problems Path of Flight says are "based upon the wind vector diagram." So, there are even more ways than just two to draw a wind triangle if Method A is considered one of them. Such as, finding wind direction and velocity, finding the turning point toward an alternate airport, and finding the radius of action. The video makes it look like this is the same problem which can be solved in one of two ways, which it is not. In order to draw Method A, you need to first know the heading. Method B is used to "find" the heading before you even take off, which is why we use it to educate students, right?

That said, even the FAA first uses Method A, meaning a short sketch upwind of the desired course (shown by dotted lines), as a way to set the scene. Then they switch to a more practical application by drawing the other half of the rhombus to scale with measuring instruments to find the true heading. That is what they, imo, refer to as the "Wind Triangle".
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Method A and Method B is simply where you chose to place the wind direction/velocity. For some learners, Method B is an easier to understand diagram, but if you only learned Method A, that’s ok too.
 
Clip4 said:
Method A and Method B is simply where you chose to place the wind direction/velocity. For some learners, Method B is an easier to understand diagram, but if you only learned Method A, that’s ok too.
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How do you know the TH for Method A without a lot of trial-and-error plotting different places to plant the wind vector? Method B always plants it at the departure point, fast and easy. Then, as soon as you swing the TAS arc from the head of the wind vector you can measure the WCA and find TH at the same time before you take off. Method A is for in-flight (have fun teaching that to a student pilot at the controls), after you already found the TH by pilotage, in order to then find your TC. The reason why you might want to know the TC after becoming airborne, though, escapes me.
 
dtuuri said:
Drawing a wind triangle the FAA's way is "the navigation way", no doubt because it's easier and more accurate. Your way has two pivot points as you swing the arcs. The FAA's way has only one pivot and can be done with a common plotter. So, imo, the OP should learn that way and teach that way rather than explain algebra and trig, which most student pilots don't have a grasp of.
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That's a valid observation.
 
sarangan said:
That's a valid observation.
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On the other hand... :) the OP could teach "carpenter geometry" instead of trig to set the scene with this analogy: Say an ultralight wants to fly 80 miles to the east with a wind from the north at 30 and a top cruising speed of 50. How long will it take? Ans.: By way of a 3/4/5 right triangle, the GS is 40, so it'll take 2 hrs. Therefore, if Google's Gemini is right, the WCA is 36.86° to the left of 090°, which also gives the TH (or he can use a protractor).
 
dtuuri said:
According to PHAK: "Either consciously or unconsciously, every good pilot thinks of the flight in terms of wind triangle." Which is why the OP wants to know more — he's preparing to teach it.
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I think that's why I struggled with the concept. It's such an innate part of flying that I don't visualize the graphical triangle or vector math. I look at which direction I plan to fly, I look at the wind direction and speed, visualize/ballpark the correction angle, then use either the E6B or digital flight computer to run the actual numbers and solidify the planning process(fuel, ETE, etc). Knowing that once I'm in the air, no matter how many triangles I drew, reality will always be at least slightly different and require further "seat-of-the-pants" correction on the fly.

I will sit down and learn this method just to be familiar with it. But as far as teaching the concepts, I feel like I'll gravitate toward the way that I learned on the E6B:
-Set grommet at 100kts (just to have it at a round number)
-Spin the dial to wind direction
-Place a dot at wind speed(e.g. if it's 15kts place the dot at 115)
-Spin the dial to the true course
-Slide the dot to the planned TAS
-Read GS at the grommet
-Read the correction angle and add/subtract mag variation to get your mag heading.

Just thinking out loud here, I'm not sure how beneficial teaching the triangle method would be. It strikes me as abstract with a high potential for confusing students without a background knowledge in mathematics and trigonometry. If manually running the vector math is what works for you, fantastic. But I think it could be a distraction or barrier to effective learning for a lot of people. And yes, I realize that spinning the whizwheel is just doing the vector math. But the process is structured in a way that's much more conducive to learning to fly, rather than a re-flavored high school math class.

With that being said, I see tons of value in initially learning on the E6B. It gives you all the numbers you need, while still reinforcing the importance of each individual step/factor in the planning process. As opposed to digital flight computers and/or plugging your flight plan into a magic box that spits out full navlogs. Once a student has a strong working knowledge of what/where/why/how the numbers come into play, then modern calculators/apps become that much more powerful as tools in the bag.
 
drummer4468 said:
Just thinking out loud here, I'm not sure how beneficial teaching the triangle method would be. It strikes me as abstract with a high potential for confusing students without a background knowledge in mathematics and trigonometry. If manually running the vector math is what works for you, fantastic.
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The wind triangle isn’t doing any math. It’s a graphical way to find wind correction angle and ground speed. It requires only a plotter.
 
MauleSkinner said:
The wind triangle isn’t doing any math. It’s a graphical way to find wind correction angle and ground speed. It requires only a plotter.
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Yeah, I thought he meant to reply to somebody else. I'm the one pointing out how easy it is without trigonometry. No cosine laws to slow me down. What can be easier than showing a student how far the airmass drifts in the first hour before drawing a course through it back to your proposed track? Getting across the idea that once an airplane leaves the ground it feels no wind other than relative wind is an important building block of knowledge. The wind triangle illustrates that principle perfectly.
 
I plug the waypoint into my EFB, start flying along the magenta line, and adjust my heading until current track arrow matches bearing. No math! :biggrin:
 
Ed Haywood said:
I plug the waypoint into my EFB, start flying along the magenta line, and adjust my heading until current track arrow matches bearing. No math! :biggrin:
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:yeahthat: , but once I'm on track I also update my paper log on my kneedboard with the correct heading, just in case of a GPS or electronics issue.
 
dtuuri said:
Yeah, I thought he meant to reply to somebody else. I'm the one pointing out how easy it is without trigonometry. No cosine laws to slow me down. What can be easier than showing a student how far the airmass drifts in the first hour before drawing a course through it back to your proposed track? Getting across the idea that once an airplane leaves the ground it feels no wind other than relative wind is an important building block of knowledge. The wind triangle illustrates that principle perfectly.
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Apologies, not intending to argue at all. Admittedly I still haven't had time to sit down and study it myself, and I think I'm grossly overcomplicating it while conflating the info between various posts throughout this thread. I'll carve out some study time tomorrow. From what I'm reading here, I'm sure I'll be facepalming over how simple it is. Really appreciate everyone's input!
 
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