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7 Answers

Wind Vector Angles?

Asked by: 4698 views
General Aviation

In general, is it accurate to say that if the angle between the direction the wind is blowing from and your direction of travel is less than 90 degrees (i.e. an acute angle), that some component of that wind would be a headwind (and not a tailwind)?

Conversely, I would asssume that if the angle between the direction of the wind and your direction of travel is more than 90 degrees (i.e. obtuse angle), that some component of the wind would be a tailwind (and not a headwind).

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7 Answers



  1. Jim Foley on Feb 05, 2011

    That would be one way of looking at it.  Just get out your E6B, and compute the cross/headwind just lik you normally would.  Substitute you course for the runway bearing, and you will get the exact value.

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  2. MaggotCFII on Feb 05, 2011

    If you are thinking takeoff/landing environment then:
     “Goggle” for Wind Component Chart or Crosswind Component Chart, you will find several versions to choose from – some include the effect of a tail wind.
    Print one off on a 5″x8″ card and include it with your checklist.  These work fine for takeoff/landing info. 
    If you are looking for wind & navigation the E6B type “wiz wheel” as Jim stated is what you should use.

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  3. Kent Shook on Feb 05, 2011

    Generally correct – To make it 100% correct, you would have to say the difference between the wind and your *heading* (not “direction of travel,” aka course) would be acute or obtuse.
     
    For example – Say you’re flying a 100-knot airplane, your course is due east (090) and the wind is blowing from 350 at 50 knots. Your heading will need to be 061 (or WCA 29º left) to compensate for that huge crosswind component, and thus the wind will become a headwind. Interestingly enough, this shows that the wind can be either a headwind or a tailwind at some angles to the course! If the wind is still blowing at 350 but it’s only at 10 knots, the wind correction angle is reduced to only 6 degrees left, and there’s a slight tailwind component.
     
    This exception to your statements is somewhat rare and only happens when the wind is fairly close to a direct crosswind, and the wind speed is a large percentage of the aircraft’s true airspeed.

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  4. Flight Student on Feb 05, 2011

    Can one ever have a crosswind and a tailwind…with a SMALL component of headwind (or, vice versa)?
    Or, can you either have a headwind or tailwind…but NOT BOTH..?

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  5. Student pilot on Feb 05, 2011

    And I suppose one could have a tailwind based on true course…crab into the wind…and have a headwind based heading.

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  6. Wesley Beard on Feb 06, 2011

    It’s not possible with a steady wind to have both a tailwind and a headwind.  If the wind is quite turbulent, then all bets are off.
     
    The formula to calculate your compass heading is True Heading +/-True Wings = True Course +/- Magnetic Variation = Magnetic Course +/- Deviation = Compass Heading
     
    When you have a true wind that is a tailwind when you crab will remain a tailwind for the calculations.  There is nothing to worry about there.

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  7. Kent Shook on Feb 08, 2011

    I think Wesley meant “True Winds” not “True Wings.” 😉
     
    Flight Student – You have one or the other at any given moment. Momentary gusts excepted, if your groundspeed is higher than your true airspeed you have a tailwind component, if your groundspeed is lower than your true airspeed you have a headwind component. If they’re equal it’s a direct crosswind, if you’re not crabbing and they equal there’s no wind.
     
    Student Pilot, that’s exactly what I was talking about in my previous answer, but I was merely pointing out that *heading* is what is important when calculating headwind/tailwind, not just *course*. If you read the example I gave, you’ll see it’s a situation where looking at the winds aloft vs. the course alone, you might think you would have a tailwind – But, when you look at your heading, it’ll actually be a headwind. Make sense?

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