Bashing my head against the wall

[flying dog]

Hi folks.

 

I just got the March "Sport Pilot" mag.

 

On about page 35 (or 7) there is an article on E6B by Paul Smith - I think.

 

(There is a problem with the page numbers given in the index and where the actual article starts)

 

He says he understands all that kind of stuff as he is uses it in his work. Terriffic! Just the person I want to talk to about it. Other people who understand maths look at the E6B and give up. Most pilots who use it don't understand the maths in HOW it works.

 

So:

 

I ran the mag and asked for help in either me getting in touch with him or leaving my details and he can get in touch with me.

 

Reply:

 

I don't know who he is or how to get in touch with him - this is THE PUBLISHER!

 

ARGH!

 

I would like to talk to him with some questions, but am now at a complete loss how to find him.

 

Anyone?

 

 

[Gnarly Gnu]

Relax Dog, try 'Clansman' on here.... I would think one and the same Paul Smith SI.

 

 

[aj_richo]

Perhaps in the meantime you could refer to http://en.wikipedia.org/wiki/E6B and delight in the mathematical formulas presented?

 

 

[flying dog]

aj,

 

Yeah, I've seen all the "tricks" on the iter-web.

 

I am sure they are right and the maths can't be faulted.

 

But I would (for some reason) like to talk to someone about it so I am 100% sure it is right and not an error in which I belive and may one day come back to bite me.

 

Gnarly,

 

Thanks much. Shall PM him and check.

 

 

[flying dog]

Update:

 

Gnarly,

 

Seems Clansman doesn't want people to look at his profile and I am forbidden from starting a conversation with him.

 

So much for the nic-name.

 

He seems to be more a loner than a clansman.

 

 

[Gnarly Gnu]

Oh well, perhaps you are the wrong clan!

 

Why not start a new thread with your E6-B questions?

 

 

[flying dog]

Well, I have in the past and it kind of died.

 

I would like to "talk" to Paul and ask if what I understand to be right is or not.

 

I've asked other people in the past and not really got an answer to my question.

 

 

[Yenn]

I can't recall any recent questions about the E6B, but it is a fairly simple tool to use. Try us again with your questions, rather than alluding to what to us are unknown questions.

 

 

[flying dog]

This will take a couple of posts.

 

Partly because I don't have the link here - now.

 

(This is going to be badly formatted and stuff like that - I am really not running on all systems just now)

 

I once asked someone and their answer was pretty well 100% correct:

 

Use it how the instructions tell you. If you use it another way, you CAN/MAY get errors.

 

This is true and effectivly irrifutable.

 

But I'm me..... and I seem to like asking questions and trying things different ways.

 

Ok, the back of the wiz wheel has the graph and the plastic disc.

 

The premise is that it is used to create a triangle and resolve vectors of course, wind and drift.

 

The first stupid thing is if the wind is 360 @ 30 (let's keep it simple and say Magnetic) you turn the wheel so 180 (or the reciprical heading) is at the top and draw a circle 30 units BELOW the centre circle.

 

Then you turn the wheel so the course is at the top and you slide the wheel so the IAS is in the drawn circle.

 

You then read your ground speed from the centre circle.

 

You get drift from the angle/line on which the drawn circle appears.

 

Yeah, badly explained. I am going from memory.

 

INDULGE ME!

 

Q1:

 

Why complicate things by turning the wheel so the reciprical heading is at the top and putting the circle BELOW the centre one?

 

Wouldn't it be simpler to put the heading at the top and put the circle ABOVE the centre one?

 

It gets the same result!

 

Q2:

 

Think about this:

 

The triangle is supposed to be a "vector diagram" of your IAS, wind speed/direction and your Ground Speed.

 

Given your plane's IAS/TAS (what ever) is "fixed", why also complicate things by making that the DRAWN circle and draw the vectors around the centre circle which is your IAS?

 

How the triangle is drawn as per instrucions, the ground speed is the centre circle and the IAS is drawn.

 

Your plane is flying 360 with a wind of 360/20

 

With the wheel having 360 at the top, instead of putting the wind circle ABOVE the centre circle, sliding that circle down to your IAS and reading your ground speed from the centre circle, why not put the wind circle BELOW the centre circle.

 

Then, you put the centre circle on the IAS, and read the G/S from the drawn circle.

 

This way you don't have to keep sliding the disc every time you have a heading change.

 

The link - which I shall post when I get home and remember to include - is a JAVA SCRIPT example of the two ways to use the wizz wheel.

 

As per the instructions and the way I suggest.

 

BOTH GIVE THE SAME ANSWER!

 

To me, it begs the question why don't they promote this "other way" to new pilots as it is so much easier to get your head around and REDUCES THE POSSIBILITY OF MAKING MISTAKES because you set the centre circle on your IAS and then only turn the wheel.

 

The other way you have to keep adjusting/sliding the disc with every heading change and it is easy to forget.

 

Granted the drift is reversed, but this is easily overcome on new wheels in that they simply stamp the oposite way. left is right and right is left for drift.

 

It isn't that difficult.

 

But my question is HOW does it work both ways?

 

Ofcourse I need it in words I can understand.

 

I know it is complicated and I need to "talk the talk" if I want to ask such questions, but ya gotta start somewhere.

 

 

[ossie]

Not quite sure what you're trying to say, but if you are placing the reciprocal heading under the True Index....you have a fundamental misunderstanding of how to use it.......

 

If you're in Sydney, am happy to sit down with you to clear things up....

 

 

[flying dog]

Ossie,

 

That worked well didn't it.

 

As I said, it is "confusing" how it is discribed and how others explain it.

 

MASSIVE UPDATE:

 

Last night while I had a few non-busy moments I got out mine AND the instructions.

 

I sat there and found the part where they "explained" how to do wind calculations.

 

Read, do, read, do, read..... HANG ON!

 

THE INSTRUCTIONS DON'T MATCH WHAT THEY ARE DOING ON THE DIAGRAMS!!

 

No wonder I am confused.

 

I shall try to find time to scan the page and include it here so if other people are also confused maybe what I have discovered will help them as well.

 

Though I am still interested in the TWO ways to use it.

 

 

[Guest Howard Hughes]

Get a CR3, 4 or 5 and ditch the E6B!

 

http://www.stefanv.com/aviation/flight_computers.html

 

 

[BruceScott]

Hi FD

 

There 2 ways of calculating wind drift and both work out, there was a thread that I answered a month or 2 ago that covered this very topic.

 

I will see if I can find the link to the thread and put a link to it here.

 

cheers

 

Bruce

 

 

[flying dog]

Bruce, thanks.

 

I hope it helps me.

 

(But I've been told many MANY times: I'm beyond help!)

 

 

[flying dog]

Update to my update:Ok, I tried to scan and OCR the text, it seems it isn't going to happen.

 

Here is an extract from the manual.

 

QUOTE

 

(excuse any spelling mistakes, I am touch typing it in real time)

 

Solution to type 1 wind triangles

 

Given:

 

Wind directio 45 deg

 

Wind speed 20 mph

 

true heading 276 deg

 

true airspeed 130 mph

 

Find:

 

true course

 

ground speed

 

Solution: See fig 1 (yeah ok.)

 

1 - set wind direction (45 deg) opposite true heading index by rotating compass ring.

 

2 - move slide so as to place any conveninet whole number under grommet (centre of rotating disc)

 

3 - Draw a line from the grommet 20 units (10 spaces) placing an arrow at the end of the wind line.

 

(Strange they don't specify the direction - but it it TOWARDS YOU)

 

4 - Rotate compass ring so that the true deading (276 deg) is opposite the true heading index.

 

5 - move slide so that the true airspeed (130 mph) is under the grommet

 

6 - ground speed (144 mph) is read at the end of the wind arrow along the speed circle.

 

7 - since the wind is fro the right, the drift is left (6 deg). The end of the wind arrow is 6 spaces to the left of the true eading-airspeed line.

 

8 - Opposite 6 divisions to the left of the true heading index, read true course (270 deg).

 

Now, thinking about it again, it may be right. What I was "reading" was it showed you your course to steer. But obviously it doesn't.

 

Somehow I think I should stop digging (talking) as it would now seem that things are "correct".

 

However, I am still stuck on the other way the school told us to do things which was as confusing as....

 

And probably didn't help me pass the exams.

 

As I said, I shall shut up now.

 

 

[ossie]

Update to my update:Ok, I tried to scan and OCR the text, it seems it isn't going to happen.Here is an extract from the manual.

 

QUOTE

 

(excuse any spelling mistakes, I am touch typing it in real time)

 

Solution to type 1 wind triangles

 

Given:

 

Wind directio 45 deg

 

Wind speed 20 mph

 

true heading 276 deg

 

true airspeed 130 mph

 

Find:

 

true course

 

ground speed

 

Solution: See fig 1 (yeah ok.)

 

1 - set wind direction (45 deg) opposite true heading index by rotating compass ring.

 

2 - move slide so as to place any conveninet whole number under grommet (centre of rotating disc)

 

3 - Draw a line from the grommet 20 units (10 spaces) placing an arrow at the end of the wind line.

 

(Strange they don't specify the direction - but it it TOWARDS YOU)

 

4 - Rotate compass ring so that the true deading (276 deg) is opposite the true heading index.

 

5 - move slide so that the true airspeed (130 mph) is under the grommet

 

6 - ground speed (144 mph) is read at the end of the wind arrow along the speed circle.

 

7 - since the wind is fro the right, the drift is left (6 deg). The end of the wind arrow is 6 spaces to the left of the true eading-airspeed line.

 

8 - Opposite 6 divisions to the left of the true heading index, read true course (270 deg).

 

Now, thinking about it again, it may be right. What I was "reading" was it showed you your course to steer. But obviously it doesn't.

 

Somehow I think I should stop digging (talking) as it would now seem that things are "correct".

 

However, I am still stuck on the other way the school told us to do things which was as confusing as....

 

And probably didn't help me pass the exams.

 

As I said, I shall shut up now.

Okay, can see now where you're going wrong.....

 

Here's how to solve the problem in your example -

 

1. place wind (045/20) UNDER True Index, if the instructions you're reading say 'opposite' they actually mean UNDER

 

2. mark wind speed (cross) (20kts) UP from the centre. In the photo below I've marked it from the 100kt mark, you can mark it from any speed mark. I've also drawn the wind vector to help visualise (In your example the wind is coming from 045T at 20kts).

 

 

Now,

 

1. rotate compass ring so True Track (276) is UNDER True Index, again if the instruction you're reading say 'opposite' they actually mean UNDER.

 

2. move card so TAS (130kts) is under your wind mark (cross)

 

3. read drift, in this example = 7deg right, then read your Ground Speed = 141kts

 

So the answer is -

 

276 + 7 = 283T and a Ground Speed of 141kts.

 

 

And, don't forget to apply the Magnetic Variation to determine your Magnetic Heading :))

 

The best way to help visualise is to draw your track and wind direction on a map, that will clear up any confusion....

 

Hope the above helps :))

 

 

[flying dog]

Yeah, that is ONE way.

 

The instructions I posted were not the same.

 

Your way you have to read the G/S from the centre GROMIT. My way you read the TAS from the GROMIT - and so the G/S is shown at/on the pencil line.

 

Your way, every time you change heading, you have to slide the wheel so the TAS - which is constant - is on/under the pencil mark.

 

EASY TO MAKE MISTAKES.

 

The way I discribed reduces the need to slide the wheel.

 

These two ways seem to work. Bu&&ered if I know why. No one can tell me.

 

Anyway, back in 1988 (That long ago!) The thing I bought had its instructions written one way, and the instructor was advoating the way you discribed.

 

Talk about confusing!

 

So, really it hasn't helped me. I know both ways work. But I don't know why.

 

 

[Yenn]

Ossie.

 

I looked at what you have and am amazed works. It is not the method I use, but your estimation of the drift is incorrect. With 045 wind and 276 track, drift will be to the left.

 

My method, put wind direction under the index, put TAS at the ctr of the disc, mark an arrow head down from the ctr grommet equal to wind speed. Now set up desired track at the top index and you can see drift by the wind arrow head. Adjust heading so that heading plus or minus drift equals desired track and you have the heading to steer and the wind arrow head is on the GS. I think that is Flying dogs method.

 

 

[Tex]

Ossie.but your estimation of the drift is incorrect. With 045 wind and 276 track, drift will be to the left.

Hence heading offset to the right (+degrees for true heading) so his estimation is correct

 

 

[Tex]

They both work because you are still creating a correct vector diagram, however asking a different question: one asks to indicate the drift you are encountering (flying dog) the other the correction for drift (ossie). Simply, all you have done is move the reference to a different point, above or below the datum, the maths is exactly the same you are just asking a different question, for a different answer, that requires the opposite application (as the reference is opposite).