Archived

This topic is now archived and is closed to further replies.

speedimikey

ND and VOR radials Do Not Align

Recommended Posts

Hi Everyone,

 

The ND in PMDG737NGX and 777 do not align with SID's VOR radials. It is off by 3 degrees either the GPS data is wrong to the right or the VOR radial is off to the left. I've tried to fix this by replacing latest Magdec.bgl file but do not work. Is there a solution to this? Check the screen shot below. The ND is showing SID PORTE5 for KSFO and the VOR radials showing PYE radial 135 outbound and OSI 285 inbound as published for the first picture. On the second picture I turned radials 3 degrees to the right which is closely aligned with GPS data. Thanks in advance for your help. By the way, Navdata is the latest that came with PMDG777.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

VOR Radials are determined by the magdec that is set on the VOR (both IRL and in the sim).  Don't know about other countries, but FAA only adjusts VORs every so often, so the magnetic course (which is what magdec.bgl controls in the sim) that you are following when "on"  a radial may differ.

 

According to FAA data VORTAC OSI is set 1975/E17 and VORTAC PYE is set 1980/E17 (so they haven't been adjusted for a long time).  That is the same as in the sim NVX file for these VORs.  So I loaded up a flightplan in the default C172 and opened the GPS and yup, like you say the mag course is 138/288 to/from fix PORTE.  So I slewed on top of PORTE and checked the radials and just as indicated on the chart, 135 and 285.  The magdec at that location in the sim is E14.4 so it differs by 2.6 degrees.  FSX is working exactly correctly.  Don't have those PMDG planes so can't help you there, but I'm guessing what you are seeing is correct.

 

Bottom line is, VOR radial <> the mag course to fly.

 

scott s.

.

Share this post


Link to post
Share on other sites

VOR Radials are determined by the magdec that is set on the VOR (both IRL and in the sim).  Don't know about other countries, but FAA only adjusts VORs every so often, so the magnetic course (which is what magdec.bgl controls in the sim) that you are following when "on"  a radial may differ.

 

According to FAA data VORTAC OSI is set 1975/E17 and VORTAC PYE is set 1980/E17 (so they haven't been adjusted for a long time).  That is the same as in the sim NVX file for these VORs.  So I loaded up a flightplan in the default C172 and opened the GPS and yup, like you say the mag course is 138/288 to/from fix PORTE.  So I slewed on top of PORTE and checked the radials and just as indicated on the chart, 135 and 285.  The magdec at that location in the sim is E14.4 so it differs by 2.6 degrees.  FSX is working exactly correctly.  Don't have those PMDG planes so can't help you there, but I'm guessing what you are seeing is correct.

 

Bottom line is, VOR radial <> the mag course to fly.

 

scott s.

.

Thank you Scott.

 

That explains why some VOR radials match closely to GPS data than others. So for those have not updated for a long time, I have to adjust 3 degree or so in order to fly the published procedures by VORs and NDBs.

 

Mike H

Share this post


Link to post
Share on other sites