Hello! 

I am planning an IFR flight and I noticed that when I measure distance from VOR to a waypoint it shows me two different numbers for magnetic radial. Like 360M > 4M. What does it mean?

Second question - I inserted approach path to land at the airport and it shows me heading 284 while the ILS says it is 281. Why there is a difference?

 

Ok, I figured it out.

VORs have calibrated declination which is why I see two numbers on the bearing.

VOR's calibrated declination might be different from the magnetic declination in the area.

An example:

let's say we need to fly to the true north using VOR. Local magnetic declination is 11east. So, if we were to fly using just magnetic compass we would keep 349 heading. it's 360-11 = 349.

Our VOR has calibrated declination 15east. Which means we need to set CDI to 345 if we need to fly straight to the true north with the help of VOR.

So, if the MD is 11east and VOR CD is 15east then we will fly with CDI set to 345 while keep 349 on the magnetic compass. These are two numbers I see on VOR bearing as 345 > 349. 

A great circle line has constantly changing heading. Also a different declination at start and end (if not using VOR ). Whats shown depends on configuration in options on page "Map Display 2". What you see is probably start and end course.

Have no access to my computer. So I hope I'm correct. Thera also new display options 2.7 alpha.

Here is some more information how LNM handles this in flight plans:

https://www.littlenavmap.org/manuals/littlenavmap/release/2.6/en/FLIGHTPLAN.html#magnetic-declination

Alex

Hi Alex,

I have started to make more use of the "Measure Distance from Here" feature since flying the new C208 Analog and using the KNS-80 RNAV.  However, I can't seem to get the accuracy I need.  So, after some investigation, including reading the appropriate sections of the LNM manual again...and reading this post, I have some questions.  I am using version 2.6.19 of LNM.

• The manual clearly states that the bearings shown with "Measure Distance from Here" feature are "True"...however the flag clearly says "M".  Please clarify.
• Since I get two bearings do I want to put into the KNS-80 the 1st number or the 2nd number...or do I use an average of the two?

Thanks,

Garry

23 hours ago, flytriman said:

The manual clearly states that the bearings shown with "Measure Distance from Here" feature are "True"...however the flag clearly says "M".  Please clarify.

The legend is correct and mentions true and mag. The description in the manual is an oversight.
You can configure the measurement line labels in options on page "Map Display 2".

23 hours ago, flytriman said:

Since I get two bearings do I want to put into the KNS-80 the 1st number or the 2nd number...or do I use an average of the two?

Why put bearings into the GPS? Normally you add waypoints and the GPS calculates its bearings.

Alex

 

 

Hi Alex,

Thanks for the reply.  I do see now that I can set the "T" vs "M" as I want so that is clarified.

The KNS-80 is not a GPS unit.  It was a very early unit (referred to as an RNAV...although by todays use of that term it's not exactly accurate) that allowed pilots to virtually move a VOR to somewhere else and then the unit would provide a signal to the HSI so that it acted just as if there was a regular VOR at that virtual location.

I'll go ahead and post the question on the MSFS forum for the Analog C208B to see how others are handling.

Again thanks,

Garry

Hi Garry,

I see about the KNS-80. Sounds like an interesting unit. I like this old simulated stuff.

The problem with the Great Circle route is that it does no have a constant course. You can ignore this for short legs but not for longer ones. I remember the Lindbergh mission (was this in FS9?) where the mission briefing mentioned to change heading about one degree every hour to take this into account when crossing the Atlantic.

Alex

I think your right…it was FS9.  Talk about this “classic” technology…flying the B247 with the “Radio Ranges” took awhile to master, but great fun once I did.

Garry