Wind Direction & Speed

Wind in aviation is always given in both direction and speed.   Eg: 090/10 means blowing from 090°at 10 knots.

For navigation purposes , often wind is different speeds and direction at different altitudes , in this case it is written as :


2000           5000          10000

070/15      080 / 25     090 /40


In navigation we use this variation in winds to help reduce flight times and improve fuel efficiency or flying range.

Eg: Using the above examples , if you were heading east you would be best to fly lower and fly higher if heading west.


Variable Winds

When wind speed is below 6 knots, wind is generally given as variable or VRB.  These light winds often change direction and are reasonably insignificant to all except slow aircraft. We plan for no wind when winds are quoted as variable or calm.


Winds Effect For Navigation Purposes:

  1. Headwinds slow us down and we use more fuel for a given distance
  2. Tailwinds speed us up and use  less fuel for a given distance
  3. Winds from side on blow us off course, if we don’t allow for it in our heading
  4. Tailwinds improve glide range when flying near unsuitable landing areas
  5. Crosswinds may make landing difficult or unsafe at destination
  6. Gusting winds make flying difficult and less comfortable
  7. Winds can create dangerous turbulence as they blow past mountains or hilly terrain


Safety Note

Always use wind forecasts for pre-flight planning and always adjust flight plans with new fuel and time calculations if headwinds are making you slower than planned.

Winds Sources

Your winds are available from the BOM website or NAIPS app. in the form of GPWT.

Other weather is in the form of a GAF.

TTF’s and TAF’s will also be required. Where both are available and current, the TTF’s must be used.

Whilst other weather services may be helpful in forming a mental picture, if a weather forecast is required, you must use the airservices sources.

Fun Wind & Weather Tool For Visual Learners,-31.152,152.254,8