RNAV (RNP) Tracking Error

[downscc 1,327]

As I'm adding the dozen or so new RNP approaches for cycle 0709, I've started thinking about something I sure would like to see in the next FMS (Perhaps 737NGX): The rules require that the pilot have a continuious display of tracking error.. this is nomally displayed as a course deviation indicator (which we don't have) and crosstrack error (in nm). This hasn't been an issue in most cases but as RNP0.3 becomes more common and the new ARINC424 FMS takes shape, I sure hope this gets added to the "wish list."Along the same lines, but with a wider application, is the ability to define altitude constraints differently. As they work now, the FMS commands the aircraft to level off at a hard constraint. The problem is in many RNP approaches there are "descend thru" altitude constraints (see DCA RNP 19) where you don't want to level off at the fix but you do want to be in a constant descent rate descending through the constraint at the fix. Big difference and impossible to program in current language. This feature would provide more realistic STAR descent profiles as well.Maybe Ryan can add these to the wish list we started a couple of months ago.Thanks,

[Tabs 2,790]

Dan,Will definitely pass this along to EV for consideration.

[Guest D17S]

RNP .3 and "Decend through" vertical fixes? Sounds like we're getting closer and closer to that GPS glideslope. I understand Airbus has vertical GPS positioning enabled in their latest FMS incarnations. Any updates? Is it certified?

[downscc 1,327]

If you are referring to LPV approaches, there are plenty. We are getting ready to upgrade our Garmin 530 to WAAS and verticle guidance in the C414... sure would like to see the PMDG Boeings stay ahead of the Cessna.