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RNAV1 "mandatory" to fly an ILS - a novel idea...

RNP APCH is a nav spec (as is RNP1). The approaches are hybrid, in that they use RNAV1 guidance for the initial and intermediate segments and conventional guidance on the final segment. RNP APCH is not required.

You are right, my bad “RNP ILS” for approach & missed and SID are using RNAV1 not RNP1 (RNAV1 (GPS only) OR RNP APCH), it was a free rant



Paris/Essex, France/UK, United Kingdom

bookworm wrote:

RNP APCH is a nav spec (as is RNP1). The approaches are hybrid, in that they use RNAV1 guidance for the initial and intermediate segments and conventional guidance on the final segment. RNP APCH is not required.

The US came to the opposite conclusion. By using RNP APCH rather than RNAV 1 as the applicable PBN nav specification, that allows any IFR approach certified GPS to be used, rather than restricting the operation to the RNAV 1 specification which many of the legacy GPS systems such as the KLN94, KLN89B, KLN90B, GPS155XL, GNC300XL, … that don’t support RNAV 1 but are totally qualified to fly the RNAV portion of the hybrid procedure. RNAV 1 is over kill, RNP 1 is beating a dead horse.

KUZA, United States

I think the French solution of “RNAV1 or RNP APCH” is a good one, because it allows aircraft without GPS approach certification to play the game. As usual, the Dutch solution is rather more Draconian towards GA. But I think the legacy GPS systems are less prevalent in Europe, as the GNS series was available long before we got any GPS approaches!

It isn’t just GA.

In fact GA barely features in airspace planning IMHO.

I think the main factor is “airliners” without GPS approach approval, which have been very common and probably still many exist today, especially in the older airframe sector (cargo etc).

Administrator
Shoreham EGKA, United Kingdom

Certainly. But I think the PBN Ops team in the DGAC is much more GA savvy than in the NL CAA, hence the better solution.

as the GNS series was available long before we got any GPS approaches!

I think the first standalone GPS approaches in Germany were devised in 1998, and the GNS came out in 1999. People used way different units in these early days, like the Trimble2000 Approach Plus…

Mainz (EDFZ) & Egelsbach (EDFE), Germany

Also IMHO the majority of GNS installs from the 1990s on were not IFR legal, because the installers put them in without an AFMS and the annunciators required by the STC. I know an installer who did hundreds of GNS430s and never heard of this, and didn’t connect up the OBS X/Y/400Hz wires to it either

I know this is “picking details” but if somebody is going to give you trouble, they can do it more obviously over this than over using a KLN94 to fly RNAV1 waypoints.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

In fact GA barely features in airspace planning IMHO.

My neighbor is an airspace designer, and I’m constantly giving her unsolicited feedback.

EHRD, Netherlands
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