Drift angle identification on Jeppesen CR-3

[Zio Nick]

Dear all,

I am learning to use the Jeppesen CR-3 for wind corrections calculations.
The manual reports two examples, rather clear to follow. Once the crosswind component has been identified, reading the value under the external wheel , in correspondence of the identified crosswind component will give the drift angle.
Anyway, the drift angle scale on the middle wheel from 10 degrees onward overlays on its own values: 10 deg lays on 1 deg, 15 deg is on top of 1.5 deg and so on.
In this situation, what is the criterion to choose the correct angle?
:confused::confused:

[paco]

It's actually the sine scale wrapped around twice.

If you use the inner sine scale, you need to add .0 to the front of the digits shown. Otherwise (if the angle is larger than 5° 50´), just place the decimal point in front.

I guess you could use the inner scale for extremely small windspeeds! But for most winds just use the large numbers.

The old workbook is out of print, but there is another........ as Yoda says :)

If you're interested, there will be a CR-3 android app out very soon!

Phil

[Zio Nick]

Thanks Phil!
The android app sounds interesting... it's always handy to find a quick answer to your doubts...