True Course, Magnetic Course, Magnetic Heading, Compass Heading…Help!
This question comes from Josh:
I’ve had a little confusion with cross-country planning. It is with the magnetic and true courses. Can you tell me if this is right. When I plot the route and use my plotter, the course I get is a TRUE heading. I then add or subract the variation degree which converts it to MAGNETIC. Now, I need to put in the wind correction. The problem here is I do not know whether the wind I get from Flight Service is in magnetic or true. Could you please possibly explain this to me, sorry if my question sounds a little confusing.
Sure Josh, I’d be happy to help. I think the best way to help you is to define the terms we are dealing with a little better. I put these in the order that you would use when planning your cross country flight. We refer to this kind of navigation as dead reckoning. A lot of pilots don’t trust dead reckoning, but remember that dead reckoning is all that Charles Linbergh, Amelia Earhart and many other famous pilots had when planning some record breaking flights.
1) True Course (TC): This is the course measured from your navigation plotter when you plot your flight on your map. Remember that because of the projection of the map, it is best to read this course in the middle of the leg.
2) True Heading (TH): Now that you have a true course, we need to correct for winds which will give us a true heading. You can use a E6B or similar flight computer and forecast winds aloft to correct your true course to determine a true heading. To answer your other question, Forecast Winds and Temperature Aloft charts (FD) are given in reference to true north.
3) Magnetic Heading (MH): The difference between true north and magnetic north is known as variation. Lines of variation are shown on a sectional chart as dashed magenta lines and called isogonic lines. By adding or subtracting variation from your true heading you will get your magnetic heading.
4) Compass Heading (CH): Items from inside the airplane can actually affect the performance of the compass. Aircraft technicians take account for this and will place a placard beneath the compass displaying the errors for certain headings. These errors are referred to as deviation. By adding or subtracting deviation from your magnetic heading this will give you a compass heading. A compass heading is the direction you could turn the aircraft to that has been corrected for winds, variation and deviation. In an ideal world, this would have you following your true course perfectly that you had plotted earlier on the map.
So in review:
Course: Is always the line drawn on the chart
Heading: The direction which the airplane is pointed
Hopefully these definitions will help in the flight planning process. Most navigation logs have this laid out pretty well to help you keep the terms straight.
Thanks for the question Josh. Good luck with your training and cross country trips and…
Fly Safe!
PlasticPilot on Jun 16, 2008
Thank you for this short review. Flying in western Europe makes it easier. The variation here is approximately one degree, so it can be neglected š
Keep going with this good job.
PlasticPilot
Chris on Jun 16, 2008
I can’t remebmer where I heard this but I like it
“If it’s written, It’s True”
So if you get it off a piece of paper its true, if you call someone on the radio, its magnetic.
instructor on Jun 16, 2008
PlasticPilot: That’s pretty easy then!
Chris: I like that. I’ll have to remember that. Thanks.
Steve on Aug 23, 2008
winds aloft and forecast winds are true, ATIS and real time ATC will give you magnetic wind direction
Brandon on Dec 13, 2008
When you use a VOR signal, I assume you log that as Magnetic Heading?
Paul on Jan 04, 2009
Brandon,
If you are trying to fill in a NAVLOG based on a victor airway or radial off of a VOR you need to be careful. Remember that magnetic variations change over time. So it might be that “course” off of a VOR might have shifted since that VOR was last calibrated. You need to use your course plotter. Find the true course of that radial using the plotter and then subtract or add the variation found nearby by referencing the isogonic lines (dashed magenta) to get the magnetic course.
TC -/+ Variation = MC
To find your Magnetic Heading (MH) you would also have to account for winds which are given in reference to true north so then it would be:
TC -/+ WCA = True Heading (TH)
TH -/+ Var = Magnetic Heading (MH)
MH -/+ Dev = Compass Heading (CH)
derm on Mar 31, 2009
That was perhaps the lamest answer I could imagine. He asked a simple, specific question and you gave him a general overview that did not answer the question.
Chris in the comments sums it up in one sentence.
Hmmmm…should I trust the other things I see on this site?
Paul on Mar 31, 2009
Hi Derm,
Wow. I’m sorry if you thought my answer was lame or too verbose. I do have a tendency to carry on a bit (ask my students) and it is something I’m working on.
I do my best to be thorough and try to provide complete answers but maybe I’ll start trimming it back a bit.
Thanks for your honest feedback.
derm on Mar 31, 2009
Sorry about that comment, paul. I came into your site from google and hadn’t read anything but that one answer. I do think it totally didn’t answer the question, but there’s no reason for me to be a jerk about it. I browsed around and looks like you’ve got some cool stuff here.
Paul on Mar 31, 2009
No worries. That’s the nice thing about the internet. Everyone has a voice right? I could have never learned to fly if I didn’t know how to accept constructive criticism and suggestions. I appreciate all the feedback I get from users. That’s the only way this site will get any better.
Let me know if you need anything else.
Niku on Apr 25, 2009
Poul i find your asnswers very helpful but just a question since im a biginner..
What is the WCA? I know its the wind but what does the abreviation stand for?
Paul on Apr 25, 2009
WCA stands for Wind Correction Angle. This is usually measured in degrees of correction either positive or negative. This value is generated on the wind side of your E6B. You take your true course and then compensate for winds. If you have a left or right crosswind you’ll have to crab into the wind in order to maintain a certain course across the ground.
Kharl on Oct 16, 2009
Hi!
I found very very helpfull alll the info posted here
i use to know each concept;
TC true course
TH true heading
MC magnetic course
MH magnetic heading
CH compas heading
but i use to forget it many times too…
im lot more clear now (thanks) but i still have not understood 100%
the magnetic course (MC) and/or my question about this would be; could a course (line drawn/ plotted on a chart) not be magnetic, i mean if is not magnetic course what other course would be?
and studying ADF i found this too:
RH relative heading
RB relative bearing
i know relatevie bearing is the degrees you must turn clockwise the plane to flight in straight line to the NDB, but so, what is relative heading?
Thanks and sorry for my poor english
Rudy on Dec 13, 2009
I am confused about all things “BEARING” Need help diferentiating between headings and bearings… thank you!!!
dope32 on Jan 19, 2010
prove it steve in the far aim
winds aloft and forecast winds are true, ATIS and real time ATC will give you magnetic wind direction
Justin on May 29, 2010
Many nav logs have MC in a bigger section than the planning area that involves WCA, VAR, DEV, etc, but why do we have a MC section on the log? I’ve heard other CFI’s and students alike trying to use the CH, but completely ignoring MC to the point of not even filling it out. So, why then, is it on the nav log if it’s not being used for navigation and is not part of the planning? Even many wiz wheels don’t use it. They use TC+/-WCA = TH +/- VAR = MH +/- DEV = CH, but never say anything about MC. So why is it not in any of the formulas?
My understanding is this: Heading is the direction of the longitudinal axis of the aircraft. In navigation, the reference direction is mag norht and the heading is known as mag heading (MH). Wind can change the aircraft’s path over the ground to differ from its heading, the result being the ground track. MC is based on mag north. (Some countries refer to it as desired track.) VOR and ILS CDI’s show the aircraft’s actual ground track is deviating from the MC.
Justin on Jun 02, 2010
To answer “dope32″…..if everything had to be proven against the FAR & AIM then that would be the only books pilots would need, study or reference for aviation knowledge and continuous learning. Not sure about you, but I use all available resources. You do know that the FAR & AIM are really two separate books, right? Companies like ASA will combine them to make them easier to reference.
Anyway, you might want to open your copy of the FAR AIM and on page 821 in Chapter 7 “Safety of Flight”, Section 1 “Weather”, page 821 you’ll find the ASOS/AWSS (Metar) says wind direction in ten of degrees from TRUE north. The ASOS is Metar information which is written. This is just one example.
Additionally the Weather Services book AC 00-45F (Oct. 2007) Section 3:Observed Text Products Page 3-6 “It is coded in tens of degrees relative to true north using three figures.” Also on pages 5-21, 5-47, 5-57 etc. are good pages for you to look at. This is an Advisory Circular and while ACs are not necessarily regulatory in nature like the FAR, you’d have to agree that neither is the AIM. Yet you use that.
What I’m saying is that you can’t simply demand someone to “prove it” against only the FAR / AIM. Especially when Steve’s question was not even about regulations, but rather about information.
Jason Labrum on Aug 14, 2010
Paul,
When preparing for an instrument checkride should I be filling out a navigation log?
Or, can I simply print a Duats flight plan or use the dauntless-soft.com ifr flight planning form?
Thanks for your help
ramus on Sep 13, 2010
ok thank you
syao on Sep 28, 2010
may i know what track is? it is different from magnetic hdg and true course right?
Noobie on Jun 17, 2011
Guys,
where I am flying to, when I am flying the compass heading?
Private PILOT on May 10, 2012
thanks. this is very helpful to my private pilot examination
tobepilot on Jul 26, 2012
Hi
Could someone explain me this:
when air traffic controller asks me ” Report heading”
Do I answer with TH or TC
TC -/+ WCA = True Heading (TH)
TH -/+ Var = Magnetic Heading (MH)
MH -/+ Dev = Compass Heading (CH)
Thanks
Mike M. on Jul 27, 2012
tobepilot… Take a moment and think about what a controller has to work with… they most likely have you on radar, right? So what they care about is your ground track. They could care less about where your spinner is pointed. So if you reply with your True Course they will be happy.
Mike M.
Tom on Oct 03, 2012
Hey Mike,
I do not agree. If a controller asks for a Heading, he wants to know the Heading you read on your instruments, which is the heading you are flying. Of course many planes can view the track as well, but as all airplanes get headings to follow by the controller, it does not make any sense telling the controller the track. If they want to know the track, they will ask for a track š
cheers Tom
Michael on Nov 11, 2012
I would like to see more reference material where wind direction reported form atc or atis
is in magnetic.
Marius on Nov 16, 2012
Yeah… I have to second that. When ATC states “report heading” they want your actual heading. All their vectors are given as headings.
Karl on Nov 28, 2012
There was no talk above of Mag Track but I need to know Mag Track for proper VFR cruising altitudes(especially important near 180 and 360) I assume that is just your true track plus variation. Is that correct? Thanks
Jose Lopez on Nov 29, 2012
Thank you for the review, really helpful.
Boll Weevil on Mar 10, 2013
This is a great site. Thanks for all the information.
Garry on May 26, 2013
Some of you need to spend more time reading Airplane Flying Handbook & Aviation Weather books from FAA.gov. All the questions asked here are explained there. Never heard of ‘Magnetic Track’ as Karl referred to…? You mean Ground Track? That’s the line you’re tracing (tracking) over the ground. “Only the man in the tower is untrue”. Only ATIS is Magnetic direction; ALL others (METARS, TAF, FA ) are TRUE!
BC on Mar 13, 2014
1) True Course (TC): This is the course measured from yourĀ navigation plotterwhen you plot your flight on yourĀ map. Remember that because of the projection of the map, it is best to read this course in the middle of the leg.
What do mean because of projection?
Also if I plan a long XC, does TC change throughout, why or why not?
KW on May 14, 2014
Magnetic cours is true course corrected for local magnetic variation.
PIREPS report wind in degrees magnetic.
METAR/TAF reports wind in degrees true north.
ATIS reports wind in degrees magnetic.
Winds Aloft report wind in degrees true north.
William Lippincott on Jun 13, 2014
Since magnetic compass roses are displayed on sectional charts as well as true N grid lines, why not plan flight route and performance using magnetic course only. Why bother with TC-MC conversions?
Cosmonaut on Jul 04, 2014
Just want to say, thanks Paul for this informational site.
And also, don’t apologize to derm. He wasn’t giving CONSTRUCTIVE criticism at all, he was just being a total dick. Only after choosing not to fight fire with fire did he apologize. He came here to give his two cents and that is it.
Stay awesome Paul
Prince on Oct 28, 2014
Formula for finding True course, Magnetic course, compasss error, compass course, Deviation and variation.
Ro on May 04, 2015
Hi everyone, my question is about IFR flight planning.
imagine you are supposed to flight on airway which is 120 MC, wind aloft report shows 160/25 which is TH and VAR is 20 degree W, what is my cross wind component? 16kt or 21kt?
felix on Nov 23, 2015
Airwaycharts have the QDM to the reference VOR of the airway (not allways = MH).
Aircraft TH = MH + (var) = 120 + (-20) = 100
Wind TH = 160
difference 60
tailwind 1/3 crosswind 2/3
crosswind component 2/3 of 25 about 16
riccardo on Jan 05, 2016
how i find the TC???? i’m a student of the aeronautic school but i don’t remember the TC
PLEASE HELP ME!!!!!
Alberto on Mar 12, 2016
Thanks friend, very useful!
Ash on Aug 10, 2016
This was so helpful! I personally am very grateful you laid all the information out like you did. Sometimes answering one question can bring about a whole bunch of new questions, so it’s great to have a full reference to all the definitions and points surrounding it. Thanks!
Ted Howard on Nov 18, 2016
Small suggestion, as two of the most important things I ever learned during my years as a pilot and instructor were, 1) Attention to detail–and– 2) Words matter.
The order of flight planning to get to your final compass heading might be better served by
1. plot TRUE COURSE
2. then, instead of figuring TRUE HEADING, get MAGNETIC COURSE next by adding or subtracting the magnetic variation at this point. Reason being, you need MAGNETIC COURSE to figure your VFR cruising altitude above 3000′. FAR 91.159 explicitly says “on a magnetic COURSE of…” There really is no need to know the true heading.
3. Then add or subtract WCA to get MAGNETIC HEADING.
4. Then add compass deviation to get COMPASS HEADING.
Of course you could still plan all this as originally stated by Paul (who does a great job on this site by the way) and then mentally remove the WCA from the MAGNETIC HEADING when it comes time to determine your MAGNETIC COURSE for selection of your VFR cruising altitude above 3000′. But why add the extra step when there really is no need (IMO) in knowing the true heading? As for attention to detail and words matter…the important word(s) here was MAGNETIC COURSE, and the attention to detail was making sure you use MAGNETIC COURSE instead of MAGNETIC HEADING to determine your VFR cruising altitude above 3000′. This is especially critical when your MAGNETIC COURSE is flirting between the demarcation line between 359/000 and 179/180 on the VFR cruising altitude chart.
Marie on Jan 03, 2017
Hi!
I am applying for my private license soon and had a question regarding the WCA. How do I know if my wind correction angle is supposed to be positive or negative? Is it used to dictate east or west from the true course or true heading?
I am using triangles of velocities to figure out some E6-B problems.
Thanks!
Magnetic Compass Error Deviation on Dec 13, 2017
[…] True Course, Magnetic Course, Magnetic Heading, Compass. ā This question comes from Josh:I've had a little confusion with cross-country planning. It is with the magnetic and true courses. Can you tell me if this is […]
Ngan on Jan 26, 2018
Thanks for the post. I have a question though, why we need to calculate all these 3 headings ā true heading, magnetic heading and compass heading? isnāt it that one is enough for the trip? I self teach the ground lessons, and this is my first time learning it. Thanks!
lance Dixon on Jul 29, 2018
Paul, You handled this awkward situation very well. I commend you on you comeback. Its nice to see a pilot, let alone a CFI that is willing to peel back the ( Because I said so attitude) and be real. I can say that you taught me something about heaping coal on a head without having to shall we say get hostile or defend yourself. I will take that learning experience all day with me. be blessed
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Wyman Lee on Apr 28, 2019
Hi all,
Here’s my question. Since winds are given in true, when will I ever apply magvar to winds? If I apply magvar to the winds, do I apply it to magnetic course to give me the magnetic heading?
Separately, are headings given in Instrument Approach Plates magnetic?
I’m doing my ATP written soon and the Aviation app is giving me dubious answers ie apply magvar to winds and then using that WCA for TC and I don’t think that’s right.
Ariston
how to buy a laptop computer on Aug 24, 2020
Thanks for finally talking about > True Course, Magnetic Course, Magnetic Heading, Compass Headingā¦Help!
| Ask a Flight Instructor < Liked it!
FlopDog on Nov 13, 2021
Paul, that was a great answer and helped clarify the question for me. Thank you for the “windy” response.
Much appreciative,
Student Pilot