Exactly, cougar.

GF

I would agree with that.

Airbus calls this the FLS for "FMS Landing System". It generates an FMS-derived glidepath and extended final approach course based on whatever nonprecision approach is in the box. You DO, in fact, press the APPR button to arm it, and it arms and captures modes called F/LOC and F/GS (FMS Localizer and FMS Glideslope). Can join off the LNAV course or a heading, just like a regular ILS.

In fact the deflections are displayed on the PFD (and ND if so selected) exactly like a regular ILS but using double diamonds for the "needles". The FMS signal is actually routed through the same multimode receiver that processes conventional Localizer and Glideslope signals, which then displays the ILS lookalike indications.

Works wonderfully and completely replaces the FINAL APP mode in aircraft so equipped.

On Honeywell Apex avionics we use Approach mode for all "Localizer" type approaches; ILS, LOC, LPV, LNAV/VNAV. During last recurrent I asked about LNAV/VNAV to verify and was told yes.

The FMS VNAV path starts from 50" above the first brick of the runway and is only concerned per ARINC 424 to clear obstacles from there to the FAF. If there are no terrain or step down problems in the final segment then the angle will be 3 degrees. If there are obstacle factors in the final segment then the VNAV path will raised to clear them to a limit of 3.8 degrees "if I remember right from my FMS coding days". I.E. you are only guaranteed step down clearance inside the FAF. There is a new generation of approaches being tried out where the VNAV path will clear all step downs further out. I think you will have to activate approach mode or equivalent at a certain point.

A little light reading

https://www.faa.gov/documentLibrary/..._Circular/AC%2

090-105.pdfhttps://ieeexplore.ieee.org/abstract/document/5347485/?reload=true
ARINC 424 Navigational Data - Jeppesen

If we are talking about ARINC coded VDAs -calculated glidepaths for NPAs, they DO NOT provide any obstacle clearances between the FAF and the MAP. They are strictly mathematical computations for a TCH and FAF altitudes giving a coded angle for a displayed glidepath.

I have not NavData coded in a while but in the past and pretty sure now the VNAV path as coded in the Nav database will be raised to clear any step downs between the FAF and 50' crossing height for the selected approach. Speaking only for our airline you never have to check crossing altitudes inside the FAF using VNAV i.e. the calculated angle encoded in the Navdata base, only prior to the FAF. Also, you are really only guaranteed terrain clearance to minimums, the final segment is a visual maneuver on a non precision approach. In many FMS there can be only one approach of a given type i.e. only one VOR approach etc. a given runway. There may be a VOR DME, VOR or VOR/A also but only one in the FMS, the standard was to include the one with the lowest minimums. However with most NavData providers you have the option for tailoring the data to remove one and add another or you can backwards engineer another one if required.

I just checked with a old friend who still codes FMS Navdata and ARINC 424-19 spec is to go from 50' above the runway to the FAF and make the VNAV angle clear any step downs between the FAF and the 50' crossing height.