E6B flight computer

[PhotoBoy]

I saw a pilot calculating his heading using a whiz wheel and I was bafffled by the way he did it.
I usually set the wind speed on the wheel, put a spot or a cross above the centre point and then rotate the wheel to the ground track compass direction.

He started by putting a spot underneath. i just couldn't work out how he'd done it or why he thought this was a "less complicated" method.

Anyone help me work out what he was doing ?

[Chilli Monster]

There are two methods - "Wind up" (your method) and "Wind down". Both have the same result and both are just as good - it just depends how you've been taught.

Many feel Wind down is easier because wind direction is given as the direction FROM which the wind is coming, whereas your track (which is placed at the top of the wheel) is where you are going. It's therefore easier because it gives a true representation of the triangle of velocities.

[tmmorris]

I believe wind down, as usually taught, is also slightly more accurate, because it involves a further adjustment of the heading after the first rotation of the wheel.

Tim

[-IBLB-]

I grew up aviation wise in the US. Flying and training for FAA certificates i always got taught the "wind up" method. Not till i started teaching JAA i learned about the "wind down" method. Wind down does make more sense to me, and i use it all the time now. Also, in the JAA system is it is sort of assumed to use this system i guess. Look at Airtour/Pooleys CRPs 1 & 5 for example; the scale on top, on the windside of the CRP, says "drift". This is true using the "wind down" method; using the "wind up" method it should have read "wca". Most E6B's don't read "drift" (or "wca" for that matter") The wind down method is supposed to be a little more accurate, allthough differences are minor.

Using the wind down method is pretty much the same as the wind up method. But you start with putting the wind below the grommet, and keep the GS under the grommet.

For practical flying purposes, you can use either one.

Note: photoboy i see you are living in nottingham, and i assume it is UK. Also, you are talking about about "E6B (http://en.wikipedia.org/wiki/E6B)". There is a difference between E6B (the american style, alot of time with the little eye for hanging it in the historical cockpit) and CRP, the Circular Rotating Plotter, as mainly used in Europe.