A modern E6B flight computer
The E6B is the aviator's flight computer — for decades a circular slide rule carried in every flight bag. This is the same set of calculations, rebuilt for your phone: every figure recalculates the moment you change an input, so there's no winding a wheel or reading a cursor. Use it for flight planning, checkride prep, or a quick sanity check in the run-up. It's free, works offline once loaded, and needs no account.
Five functions are split across the tabs at the top of the page:
- Wind Triangle — enter true course, true airspeed and the wind, and read your required heading, wind correction angle, ground speed and head/cross components.
- Airspeed & Density Altitude — from pressure altitude, outside air temperature and calibrated airspeed, get density altitude, true airspeed and the density ratio.
- Time · Speed · Distance — fix any two and solve for the third.
- Fuel — solve for fuel burned, endurance or burn rate, with a 45-minute reserve figure.
- Conversions — distance, speed, altitude, temperature and fuel volume/weight.
Worked example: wind triangle
Flying an easterly course of 090° at 120 knots true, with the wind from 160° at 25 knots, the computer returns:
Under the hood this is the wind triangle: WCA = asin(WS·sin(WD−TC) / TAS) for the correction angle, and GS = TAS·cos(WCA) − WS·cos(WD−TC) for ground speed — the same relationships the mechanical E6B solves graphically.