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