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This answer from English.SE does not focus on aviation, and does not explain 'Track'.

In basic, simple English, would you please compare and contrast all 5 terms in my question's title? The differences between 'course' vs 'heading' was generously explained in this answer.

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This is how I explain it, hopefully it helps more than hinders!

Heading:
This is where my nose points - and seeing as my nose is attached to my head, this is where my head (and thus my machine) is pointing relative to North.

Course:
This is my INTENDED path of travel that I have calculated taking into consideration winds, variation and declination.

Track:
This is my ACTUAL path traveled over ground - just like a set of tracks I would leave behind in the snow or sand, relative to North

Bearing:
This is the angle between the location of an object, machine or destination and either:
- my heading. This is called 'Relative Bearing'.
- or magnetic north (direction toward the magnetic north pole). This is called 'Magnetic Bearing'.

Diagram

So from the picture, if I take off from Springfield enroute to Shelbyville. My course (the intended path) is due East, or 090 degrees. I notice my winds are Southerly (from 183 degrees / to 003 degrees), so I make my heading 095 degrees to compensate for wind drift (or 5 degrees crab into the wind).

If my calculations are bang on, my track should be the same as my course, however I misjudged the winds, finding out my resulting track over the ground is 081 degrees - I must correct (by increasing) my heading to get back on course.

Now with some airports, the navaids (NDB or VOR) are not directly at the airfield but some distance away, so if I wanted to either fly directly to the NDB or figure out my position in space during enroute nav checks, I would take the bearing to the NDB/VOR either relative to my heading or relative to magnetic north to find its position.

Hope this helps.

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    $\begingroup$ Welcome to Aviation.SE! Great answer! $\endgroup$ – Steve V. Oct 6 '14 at 1:12
  • $\begingroup$ Good answer; two small points: course is independent of wind, and the winds from the south are not generally referred to as northerly, but would be expressed as 180/50 rather than 003/50. $\endgroup$ – Ralph J May 28 '15 at 2:57
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    $\begingroup$ I fill like this picture is confusing. To my understanding from this answer, if magnetic bearing is 144 degrees (cw) and heading is 95 degrees (cw), shouldn't relative bearing be (144 - 95) = 49 degrees? If the plane was on course, then only the relative bearing at that point could be 54 degrees! Am I missing something here? $\endgroup$ – Sidmeister Mar 4 '16 at 17:01
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I will try to explain as simple as possible, though I'm not a professional.

Heading
It is the value the compass shows you while you fly your plane, relative to Earth's magnetic field. But your heading is not where exactly your plane goes. Why? because in most of the cases (if not all) there is wind.

Track
This is the aircraft's actual "path" over the ground when wind effect is "added up" to the aircraft's velocity. You need track for navigation since this is where you actually go.

Bearing
If it is from north (true or magnetic): Having two locations A and B, bearing of B to A is the angle measured clockwise from north to B having as angle vertex location A.

If it is relative: Having 2 locations A and B, bearing of B to A is the angle measured clockwise from point A forward direction to B having as angle vertex location A.

In the following picture, red is true bearing, blue is relative bearing.

True vs relative bearing

Course
This is the one and only path you can follow to reach one specific point. Suppose that you are instructed to "approach the XYZ point from the east" that means course 270 to the XYZ point. The following pictures depicts the concept: 270 course to XYZ is the green one. The red one goes to XYZ but it is not 270, the orange is 270 but doesn't end to XYZ.

Course to point explanation


For more information:

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  • $\begingroup$ Direction should be the general direction of the flight, e.g. north, east, south, west. Maybe you can incorporate this into your answer? $\endgroup$ – SentryRaven Aug 4 '14 at 10:01
  • $\begingroup$ @SentryRaven I am not sure about direction. It's becoming bit of a word play, that's why I'm using the word in quotation marks when I use it for Track. $\endgroup$ – Stelios Adamantidis Aug 4 '14 at 10:04
  • $\begingroup$ So, what's actually the difference between Track & Course? They seem to be the same: the actual direction the plane is going to. $\endgroup$ – Fox Aug 4 '14 at 15:09
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    $\begingroup$ @Fox course is where you are planning to go, track is where you are actually going. When track == course, you are "on course". $\endgroup$ – casey Aug 4 '14 at 15:11
  • $\begingroup$ @casey Thanks, that makes a lot of sense! $\endgroup$ – Fox Aug 4 '14 at 15:13
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The difference between track and heading not only includes wind, but also includes flight in sideslip due to asymmetric drag (eg engine out) or pilot induced steady heading sideslip. It also includes AoA during a turn; extreme case of 90degrees AoB at high AoA.

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