I posted this question in DAN forum for DA42 but didn’t get satisfying answer. Maybe some of G1000 users here (regardless aircraft type) have some good tips.
When I load RNAV approach (non-WAAS G1000) the distances shown in FPL inset window on PFD are relative to previous point. So the last distance shown is between last point before MAP and MAP. However, on Jepp plates distances used for vertical guidance are relative to runway treshold. The question is how to relate distances written on plates to distances shown in FPL? I.e. I’m looking for the same feature as when using DME in LOC/DME or VOR/DME approaches.
AFAIR the same issue exists in G430/530 – I don’t know what’s the situation with rest of Garmins and for WAAS enabled devices.
I know you can choose whether to display the cumulated distance or the leg distance in the G1000 FPL. That is a setting on the system page. It might also be accessible from the FPL menu page.
However after the threshold your FPL will show the go-around legs so the cumulated distance may be 0 at a point after the threshold in which case it will not be very helpful.
After the final approach fix the next WP will be the threshold, and the distance should be displayed next to the WP name at the top of the screen. I would not use the FPL inset to monitor distance to the next WP but either the distance to the next WP at the top of the screen, or the navaid indicators at the bottom of the PFD
The profile miles on the approach plate should be GPS derived and countdown to the MApt (missed approach point) you would start your CDFA (continuous descent final approach) at the FAF (final approach fix) and the distance should countdown just like on a DME derived non precision approach.
There may be a descent leg from the intermediate fix to the FAF, but this is typically a shallow descent and you would configure for the CDFA at the FAF.
I think in WAAS devices the FPL page is obliged to show you the dist from previous waypoint rather than the cumulated, you cannot change that setting. I find this frustrating as well, so while I usually rely on a collocated DME or the ETA to estimate the distance, I often also set my second GPS direct to the treshold (I don’t cross fill). It’s wrong until established on final track but it does the trick after that.
Ok, let’s put it this way, very simple question: Where do you look (for distance on your navigation instruments) during the RNAV approach when you want to cross check you current altitude with altitude/distance shown at approach plate?
…in the G1000 you would use the magenta flight strip on the PFD (Pilot Flight Display) which provides the mileage countdown to MApt.
It’s obvious 
and I haven’t asked that.
Jepp plate doesn’t show distance to MAP; it shows distance to RW threshold while G1000 shows distance to MAP. The question was how to cross check these two values.
On an RNAV approach you go-around at a specified altitude, but the waypoint is the threshold.
So you look at the magenta flight strip, or the relevant BRG information window on either side below the HSI which may be more convenient and is in close vicinity to the DME distance that you would use for an ILS, so keeps you scan more consistent.
Unless the MAPt on an RNAV has a different named identifier, the MAPt is the RW threshold. The VDP is the distance from the threshold where you would expect to reach MDA, and in a CDFA initiate a go around.
I can’t attach LGKR plate as an example because I don’t have PC here. If anyone is able to post LGKR RNAV Jepp plate that would be example of what I’m trying to understand. MAPt is pretty far ftom RW threshold and when approach is loaded to G1000 it shows distance to MAPt while Jepp plate specifies distances from RW threshold.
