HSI distance readout not working in GPS mode

[jfwharton]

This may be how this aircraft was designed but I noticed that the DIST readout on the HSI only works when a VOR or ILS frequency is dialed in and shows the distance to the VOR or ILS when in VLOC or GPS mode.  It does not show the distance to the next flight plan waypoint when in GPS mode.  Personally, I would prefer it to show the distance to the next waypoint based on GPS mode.  Distance to next waypoint when set to GPS and distance to VOR, ILS when in VLOC.

[tkyler]

the HSI LED display uses "DME" for its distance readout.  DME is a terrestrial, radio based transmitter, generally co-located with VORs (but not always) and ILS transmitting systems and hence why you'll only see distance when tuned into those transmitter frequencies.  DME is not part of the GPS system at all and so will not display on the HSI.   This is simply a classic case of putting a GPS in a 40+ year old panel

Edited July 16, 2022 by tkyler

[jfwharton]

OK, thank you.  I figured that was how it was.