Bendix/King KN 64 DME
The KN 64 DME is one of the avionics instruments in the MSFS 2020 Carenado Beech 18 and the Denarq mod (see Fig. 1). This instrument has confused me as to how it works in the simulator (MSFS 2020), so I tried all the switches and knobs while also adjusting the NAV1 and NAV2 radios to figure out how it behaved. Herein I document what I have found. Not surprisingly, the DME unit as implemented in the Beech 18 in the sim behaves somewhat differently than the real life one as described in the KN 62A / 64 manual.
In the real unit, there are three modes selected by the 3-position switch on the upper right of the unit: RMT ā FREQ ā GS/T. In the RMT (Remote) mode, the DME unit uses the frequency selected in the NAV receiver connected to the DME, generally NAV1, and displays distance, groundspeed, and time-to-station for that NAVAID. In the FREQ mode, a separate frequency for a NAVAID with DME (e.g. VOR or Localizer) can be tuned in using the inner and outer knobs on the right of the unit and it will show the distance to that station as well as the frequency for that NAVAID. In the GS/T mode, the unit displays distance, groundspeed, and time-to-station for the station tuned in with the FREQ mode. Note that for both RMT and GS/T modes, the groundspeed is the speed relative to the station. It represents the true groundspeed only if traveling directly to or from a station.
While the KN 64 unit in the simulator has the three-position mode switch, you can only select the RMT and FREQ modes. RMT behaves the same as in the real unit ā it displays distance, groundspeed, and time to station for the NAVAID tuned in on NAV1 (on the GNS 530). In the FREQ mode, it behaves quite differently than the real unit. If you use the knobs to change the frequency, it shows the change in frequency on the KN 64 unit itself, but it also changes the active frequency for NAV1 as shown in the GNS 530. However, even though it shows the frequency you selected on the face of the KN 64, this is not the frequency of the station for which it displays distance. Rather, it shows the distance to the station selected on NAV2.
To demonstrate, I took the Denarq mod Beech 18 on a flight between the Scholes VOR-DME (VUH, 113.0 Mhz) in Galveston, Texas, to the Navasota VOR-DME (TNV, 115.9 MHz) (see Fig. 2 ā snapshot from LittleNavMap). The distance between these two NAVAIDs is 87 nm. At a point between the two stations, one can change the NAV1 and NAV2 frequencies (e.g. between VUH and TNV) as well as change the mode and frequency on the KN 64. A video of this demonstration can be found on Youtube.
It should be noted that when a VOR with DME is tuned in on NAV1, the GNS 530 shows the station identifier, radial, and the distance to the station in addition to the frequency. However, when a localizer is tuned in, the GNS 530 shows the airport identifier and approach runway for the localizer rather than the radial and distance to the station. Having a separate DME instrument to show distance can be quite handy, therefore, on ILS or localizer approaches.
Here are a few key points for use of the KN 64 DME in this airplane in MSFS 2020:
- RMT mode works as expected ā showing distance, groundspeed, and time to station for the NAVAID selected with NAV1 (on the GNS 530)
- In FREQ mode, the distance to the NAVAID tuned in on NAV2 (KX 165 COM/NAV radio) is shown along with whatever frequency is currently active on NAV1.
- I recommend not changing the frequency on the KN 64 (in FREQ mode), but simply using the FREQ mode to show the distance to the station on NAV2. Thus, switching between RMT and FREQ mode can be used to switch which station is used for the distance shown on the KN 64 ā the one tuned in on NAV1 (RMT mode) or NAV2 (FREQ mode).
- Groundspeed and time to station can only be shown for the NAV1 NAVAID.
- If NAV1 is tuned to a localizer, the KN 64 (in RMT mode) can be used to show distance to the localizer which is not shown on the GNS 530.
- The ON-OFF switch on the KN 64 DME unit also controls power to the KR 87 ADF receiver.

