Pilot software except vPilot, SquawkBox, FSInn and XSquawkbox
By Markus Schober 1328585
#522508 After spending some time searching for a VOR/DME based RNAV computer from the time before GPS became a thing (a.k.a. Rho-Theta RNAV - where you virtually moved a VOR station to the desired waypoint) for flight simulator use without much success, I decided to take things into my own hands, did some research and, eventually, replicated the Bendix/King KNS 80 as a gauge for FSX. What started as a small project matured quickly and became a solution that works impressively well. Actually so well that I asked myself if I should make it available to the public.

The system consists of two gauges:
  • the actual KNS 80 RNAV computer, programmed according to the manufacturer's "Pilot's Guide KNS 80" and
  • a Garmin 102A CDI instrument, specially made for compatibility with the RNAV computer, for displaying the course deviation

The gauges contain carefully edited and thoroughly animated artwork and enact the original system's functionality to the extent permitted by the flight simulator, and just like the real computer, the gauge does all the maths with the information from the tuned VOR/DME station - there is no cheating or tampering with GPS variables.

Features include:
  • VOR mode: CDI acts like a standard course deviation indicator, the needle shows deviation in degrees, 2 degrees per dot, 5 dots from center to each side
  • VOR/PAR ("parallel") mode: CDI shows course deviation in nautical miles, 1 NM per dot
  • RNAV/ENR ("enroute") mode: CDI shows course deviation to the selected course to/from the active waypoint (virtually moved VOR), 1 NM per dot
  • RNAV/APR ("approach") mode: same as above, but 1/4 NM per dot
  • 4 waypoints (defined by VOR frequency, waypoint radial and distance) can be edited and activated using the RNAV computer's rotary knob and buttons
  • RNAV computer display shows distance, ground speed and time to station/waypoint

While the source code is authored by me, I assume that I need agreements from the copyright holders of the source images, as well as the owners of the trademarks and possibly even design patents used in the work before publishing it, even though I intend to make the gauges available for free.

So before getting headaches from that legal stuff, I would like to know first:
Is there anyone at all out there who would be interested to use these gauges?

If yes, drop me a PM.
By Markus Schober 1328585
#522538 Image
RNAV computer mounted in a virtual cockpit

RNAV Computer as windowed gauge, CDI in virtual cockpit (highlighted), GPS as proof-of-concept reference

Programmed waypoint: OKIBA, which is shown on the charts located at 109.2 LBU VOR, Radial 355, 18.1 nm (programmed radial and distance cannot be seen in the screenshot, they share the display with the frequency and are shown when pressing the DATA button)

Deviations match (GPS in TERM mode: 1 line = 0.5 nm, RNAV in APR mode: 2 dots = 0.5 nm). Distances and ground speeds match.

(You will notice that the OBS knob of the CDI, while still being perfectly operational, does not really fit into the 3D knob of the default C172's virtual cockpit. Making it fit should not be a big deal, but only if requested because I'm not going to use the system on that plane)
By Markus Schober 1328585
#522734 To everybody who wants to try the panels - the package (freeware) can be downloaded now from

Search for the file
Code: Select allrnavvordmefs9fsxv161.zip

(And yes, the OBS knob now fits into the default C172 3D panel)

[EDIT 2018-11-10: file name updated]
Last edited by Markus Schober 1328585 on Sat Nov 10, 2018 2:38 am, edited 3 times in total.
By Markus Schober 1328585
#523178 There is an update available for download from

Search for the file
Code: Select allrnavvordmefsxv15.zip

New in this version:
  • ILS mode
  • additional CDI with glide slope indicator
  • waypoint calculator (LibreOffice Calc Document) for determining radial and distance from VOR/DME stations of waypoints whose coordinates (latitude and longitude) are known
By Markus Schober 1328585
#528582 As requested, there is now a new version available which is compatible with FS2004 and FSX.

The update can be downloaded from

Search for the file
Code: Select allrnavvordmefs9fsxv161.zip

Changelog since version 1.5:
Code: Select all1.6.1   hotfix release

        * occasionally unsteady readings of Ground Speed and Time-to-Station in
          RNAV mode

1.6     compatibility release

        New Features
        * tooltips

        * sometimes unsteady needle movement in vicinity of a waypoint

        * use FS2004 XML schema for compatibility with FS2004 and FSX
        * perform complex calculations only on input change to save CPU time
        * reduced XML file size for faster loading