Heading to VOR - which is correct?

[Andy Clark 0]

Flying from KRNT to KFHR I used the CVV VOR.  The heading that LNM gave me 3 miles out of KRNT RWY 34 to go 'to' the VOR was 319 M - however the heading shown on the flight plan at the VOR where the line intersects the VOR was 315 M.  Which one is correct and why?

Edited October 25, 2023 by Andy Clark

[Gason71 130]

45 minutes ago, Andy Clark said:

Flying from KRNT to KFHR I used the CVV VOR.  The heading that LNM gave me 3 miles out of KRNT RWY 34 to go 'to' the VOR was 319 M - however the heading shown on the flight plan at the VOR where the line intersects the VOR was 315 M.  Which one is correct and why?

 

Heading is not the same what track/course 🙂
Heading is the direction in which the longitudinal axis of an aircraft is pointed. In flight plan you've got given course, but  in aircraft you have to fly at calculated heading  = course +/- correction angle (where correction angle = - drift angle). And yes, sometimes heading is the same as course but only when there is no drift angle.  
I guess, you'd got crosswind during your flight, so flying heading 319M you crossed radial 315M exactly at CVV VOR.

Regards,
Piotr

ps. more about heading, course/track, drift, etc. you can find at SKYBRARY: https://skybrary.aero/articles/heading-track-and-radial#:~:text=The direction in which the,Source%3A ICAO)

Edited October 25, 2023 by ppgas

[albar965 1,073]

Apart from what Piotr says about course and heading which is absolutely correct:

LNM shows one course (red 1 in last screenshot below) which is always the start course of the leg. This is ok for short legs where start and end course are the same and you're not flying VOR to VOR.

But on long legs there is a start and end course due to the Great Circle route and different magnetic declination at leg beginning and end (needless to say: avoid too long legs when planning a flight):

 

Then there are also courses to and from VOR (2) which have a calibrated declination and this might differ from the real magnetic declination at this place. All this affects the magnetic course but obviously not the true course. You'd rather use true course when flying in areas with a large declination (Greenland, Antarctica, etc.)

LNM can show both if you enable it in the options dialog. The table in options also shows explanations for these values.

Still not confused?🙃 Read more here: https://www.littlenavmap.org/manuals/littlenavmap/release/latest/en/MAGVAR.html

Alex