As a student pilot I wrote this simple tool to demonstrate the concept of a ‘wind star’ – an aid for light aircraft pilots navigating by ‘dead reckoning’, a basic skill in which all student pilots must become proficient.
A wind star comes in handy for practicing (or actual) ‘diversions’ – when you have to deviate from a planned route (perhaps to avoid bad weather, have a fuel emergency etc.) It allows the pilot to quickly estimate the effects of wind on a desired heading, allowing heading corrections and estimated time of arrival (ETA) to a waypoint to be made.
- Wind Direction = 150°
- wind speed = 25kts
- True airspeed = 100kts
Case 1. You want to fly a track of 225° for 25nm:
Wind correction angle = -14°, groundspeed = 91 kts
Result: Fly a heading of 211° for 19 mins.
Case 2. You want to fly a track of 315° for 25nm:
Wind correction angle = -4°, groundspeed = 124 kts.
Result: Fly a heading of 311° for 14 mins.