Aviator Watch E6B Slide Rule

This simple circular slide rule works the way your aviator watch does. For rate/time calculations it can be faster than a calculator: set the rate once and read every distance and time straight off the dial, without typing anything. If you're an aviator who would rather use a slide rule than a calculator, try this app. It is much easier than trying to punch numbers on a watch calculator. We created it for the watch, but it works on the iPhone and iPad, too. Rotate the outer ring with your finger or with the Digital Crown. Let go mid-turn and it spins on and coasts to a stop. Slow down and the crown gets finer under your finger, so you can settle exactly where you meant to. A click marks each numbered graduation passing the rate index — feedback only, never a detente, so the dial will never nudge you onto a mark you did not choose. THE FACE Three concentric logarithmic scales, drawn to…