Originally Posted by Airbubba
Step down fixes are not on the final profile path on many approaches. And even if they are, non-standard temperature can cause them to be above the extended profile. The feds have been harping on this in recent years, here is a discussion for ILS approaches, it is a similar situation for non-precision approaches with vertical path guidance:
I really don't think this is the issue, in relation to the publication of a distance/altitude scale for an NPA. From my reading of the links you posted, any step-down fix is related to altitudes, so the temperature would be irrelevant, as all aircraft that were affected by the fix (those on hte approahc and those crossing under or over) would all be affected identically. The issue in the articles was the physical location of the glidepath verses the changing altitude of that glidepath due to temperature. That is irrelevant to an NPA.
I can see no technical reason why a distance/altitude profile could not be published for this and other NPAs, as they are in other parts of the world:
http://www.airservicesaustralia.com/...ASVO01-135.pdf
Originally Posted by olasek
Yeah, I know many FMSs can handle constant angle descents but unfortunately my SR22 can't do it but instead can do LPV which most "widebodies" can't . But my G1000 can turn a given LNAV into LNAV+V and give me this desirable glide slope but it ain't guaranteed.
Yes this is not an LPV, so mention of it is irrelevant, and you are correct, real FMS can do VNAV on an NPA. But for those who don't/can't, a distance/altitude scale is the next best thing; I'm talking about "big iron" here. You are free to do what you like in your bugsmasher. Dive and drive to your heart's content; you're going slow enough not to hurt anyone (if you do it'll probably only be you and your few pax) and you don't have any stabilised approach pressures of sink rate and slope.