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JimNZ

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Neither,

The heading hold is for running autopilot and will hold your heading ONLY not altitude

Course Select and heading hold are in essence the same thing.

You will need to be careful as some Autopilot and or Navigational systems are GPS driven and some are Gyro driven, so with the Gyro ie Gyro Compass you will get progression for which you will need to compensate.

Hope this helps Jim

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The reason why there is two is, Heading is the bearing you want to fly, course is the heading you need to fly allowing for wind drift.

Isn't it the other way round? I'm not sure If I understood you correctly though.

If, for instance, you would like to follow a course of 90° and winds are coming from the right, then you have to fly a heading value higher than 90°. Which value exactly is depending on wind direction, wind strength and your aircraft's speed.

From Wikipedia

Heading = angle where your aircraft's nose is pointing to

course = angle of the intended Path

track (course over ground) = the actual path followed by the plane

Cheers, Wolfgang

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Isn't it the other way round? I'm not sure If I understood you correctly though.

If, for instance, you would like to follow a course of 90° and winds are coming from the right, then you have to fly a heading value higher than 90°. Which value exactly is depending on wind direction, wind strength and your aircraft's speed.

From Wikipedia

Heading = angle where your aircraft's nose is pointing to

course = angle of the intended Path

track (course over ground) = the actual path followed by the plane

Cheers, Wolfgang

Yep thats it, heading is where you point the aircraft, and course is where it actually ends up going. The other thing to consider is variation. This is the difference between degrees Magnetic and degrees True, which is around 12 degrees in my part of the world on the coast of NSW. The compass obviously reads Magnetic while charts are generally in True. To remember which way around they go, I was taught "Variation East magnetic least. Variation West magnetic best."

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I recall a similar question a while back... Here's a visual look at the differences...

Posted Image

Think of it as heading is from the aircraft, but course is to a fix... they can be the same like the first picture, but sometimes you want to fly to the fix from a different direction... in other words, using a different course.

The autopilot versions of these do exactly as they sound... heading hold just keeps your nose pointed in the direction it is set... Course select will attempt to hold a course to a fix (a VOR radial, localizer etc).

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Umm...maybe I've been spending too much time in tube liners. However, in these, "course" refers to a reference from a VOR/ILS/etc., and heading refers to a compass direction. As I said, I have been mainly flying tube liners. As true as course versus heading may be to magnetic versus true, I'm not so sure this is what other are referring to (i.e. magnetic versus acounting for winds aloft.

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Simplistically Heading refers to where the airplane is pointing on the compass. If your heading is 360° the airplane is pointing to north (360°). If there is no wind blowing the the airplane will also fly a course of north (360°). In real life no wind conditons rarely happen and to fly a course the heading must account for the effect any wind has on the airplane.

Example: your due south of your destination flying a course of north but you have some wind from 300° which is from the left of your nose and just like current in a river acting on a boat the airplane will be blown to the right and miss the destination passing to the right of it. To fly to the destination you have to compensate for this wind drift by pointing the nose of the airplane to the left into the wind thus your heading would be less than due north. How much is dependent upon wind speed, and airplane speed.

For simplicity lets say it points to a heading of 320° to compensate for the wind drift and the airplane flies a course of 360°

The reference from a VOR etc. is actually referred to as a "radial" and your course would be the same as what ever radial you are tracking from the navaid but your heading would be different from the course when compensating for wind drift.

8)

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to add to all of the above (different perspectives sometimes help to think around the subject), there is the navigational definition, considering heading compared to track (accounting for wind), then practically speaking, thinking of instrumentation use, you could be flying on auto pilot in heading mode with the heading knob (HDG) set to, for example, 180° (the aircraft will turn to the heading you select) but the course knob (CRS) might be set to 270° to pick up on an, for example, an ILS.

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