[AVIATION] How is it possible to find wind direction and speed in flight, so I can calculate wind correction on the flight computer?

I know how to calculate the grabing if I have the forecast info.

But... In the sky, the wind will change, so I'm asking how is ir possible to find the wind speed and direction.

5 Answers

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  • Anonymous
    5 years ago
    Best Answer

    While modern glass cockpits usually provide wind velocity information, its in flight application, unless it is way different from the pre-flight forecast, is fairly limited, even more so when the autopilot is simply tracking a GPS or radial and making corrections automatically.

    It is possible to do it if you can accurately measure all of the required parameters, heading, ground track, groundspeed and true airspeed, but frankly, if you are flying VFR, why would you. It is a simple matter of map reading.

    If you notice that you have drifted off track, then you can easily apply a correction using the 1:60 rule. This assumes that a one degree error in heading will place you one mile off track after 60 miles

    Here is an example:

    Let us assume that, after flying for 20 miles, you find yourself 5 miles right of track 60/20=3. 3 x 5miles off track = 15 miles and we will therefore be 15 miles off track after 60 miles.

    If we alter course by 15 degrees left, we will parallel our track, however, we will still arrive at a point five miles to the right of our intended destination.

    So lets say that destination is 120 miles further on. 60/120 = 0.5

    0.5 x 5 miles right is 2.5 So we need to add 2.5 degrees left to the course change we made to parallel the track.

    If we change course by 17.5 degrees left, we will again be heading straight to our destination, without using the E6B at all.

    However, on the back of many E6Bs is a window which will do a 1:60 calculation for you.

    hope that helps

    Source(s): Retired Airline Captain
    • Albannach
      Lv 6
      5 years agoReport

      Haven't been a PIC in many years but I still have my good ole E6B. I still do calculations and wind corrections when I'm bored.

  • John R
    Lv 7
    5 years ago

    It's a wind triangle, just like calculating the planned ground speed and wind correction, the only difference is that you have 2 different sides of the triangle, and have to solve for the side the represents the wind.

    But there is absolutely no reason that you should do so! You need that info for flight planning to ensure you have adequate fuel to reach your destination. Once airborne you use whatever wind correction angle you need to maintain course - the planned heading is just your estimate. You use time between check points to determine your actual ground speed and use that to calculate a new ETE, The wind speed and direction is not needed.

  • 5 years ago

    You cannot directly determine wind speed and direction while in flight. If you know your motion over the ground, however, you can infer this information from a comparison of your movement over the ground with your bearing and airspeed.

  • Steve
    Lv 7
    5 years ago

    You need to have available your heading, true airspeed, groundspeed, and course over the ground.

    BUT,

    Having amassed this info and computed the wind velocity, there is little guarantee that it will remain constant for any length of time. The computer in your GPS will constantly give you the info you REALLY need; your course and groundspeed. Not to mention your ETE, time in flight, etc,etc.....

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  • 5 years ago

    you don't. you compare your actual ground track with your planned ground track and correct your course, either double-angle or opening/closing angle correction.

    bonus question: of the two options for course correction, which one is preferable if both are applicable. why?

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