LGIO RNP Z 32 - vertical profile, and how can avionics fly this?

Peter wrote:

What puzzled me were the “SMA” numbers

My read: This is an RNP – therefore a non precision approach. The overflight-altitudes of the Waypoints are recommendations to create a smooth descent, but not mandatory.

The SMAs, however, are hard limits. Therefore between e.g. AMIVI and IO713 you could descent down to 5300 (and not lower) but in a smooth descent it it advised not to go lower than 6300ft.

What does SMA stand for?

Malibuflyer wrote:

This is an RNP – therefore a non precision approach.

RNP approaches are Cat I precision approaches if they have an LPV200 minimum. Not this particular approach, of course.

gallois wrote:

What does SMA stand for?

“Segment Minimum Altitude”.

I’ve never seen this before so I had to look it up in the abbreviations section of the Jepp Airway Manual. I wonder if this is a term invented by Jeppesen or if it is ICAO?

Airborne_Again wrote:

RNP approaches are Cat I precision approaches if they have an LPV200 minimum

I always get confused with the current naming conventions. I Thought that if Jeppesen calls it “RNP” and not “LPV” it is non precision in any case – but you are obviously right.

Malibuflyer wrote:

I always get confused with the current naming conventions.

I agree. But it seems that for the last few years or so, the naming conventions have stabilised.

My current understanding is that there are two distinct divisions of approaches:

1) Approach design types: Precision (PA)/Approaches with vertical guidance (APV)/Non-precision (NPA). PA are ILS and RNP with LPV200 minima. APV are other approaches with a glidepath such as LPV and LNAV/VNAV. The rest are NPA.

2) Approach operation types: 2D/3D type A/3D type B. 2D means that the approach is flown without vertical guidance. 3D means that the approach is flown with vertical guidance. Type A has a DH of 250’ or more. Type B has a DH of less than 250’.

What is not clear to me is how NPA’s flown as CDFA are treated. PANS-OPS states that if the approach is flown with an FMS-generated glidepath (e.g. Garmin LNAV+V) then it is considered a 3D approach and a DA should be used. If the approach is flown using a manually determine rate of descent and check altitudes, then it is considered a 2D approach and a MDA(H) should be used. On the other hand all other documents I’ve seen about CDFA (including part-NCO) states that a DA should be used even with a manually determined glidepath.

Maybe this helps? (sorry it’s in French but the graph just make sense)

https://www.ecologie.gouv.fr/sites/default/files/Guide_operations_2D_3D.pdf

Airborne_Again wrote:

What is not clear to me is how NPA’s flown as CDFA are treated. PANS-OPS states that if the approach is flown with an FMS-generated glidepath (e.g. Garmin LNAV+V) then it is considered a 3D approach and a DA should be used

I have been told that RNP LNAV flown in in CDFA following LNAV+V does not tick the 3D requirement for IR exams, it has to be LPV or ILS, but hey even senior examiners are confused on precision/non-precision vs 2D/3D…

Like AA I was always understood that a CDFA ends in a DA/DH.
I posted a long while ago that a precision approach is an approach which ends with a DH of 200ft or less. It would be true to say that this would normally be a 3D approach.
Anything above a DH of 200ft would therefore be an NPA.
This is where you get to if you cross reference all the regulations. But it still does not answer the question of why a CDFA, which would normally follow on from a NPA ends in a DA/DH. I can’t find the cross references for that.That graphic doesn’t really answer the question.

gallois wrote:

I posted a long while ago that a precision approach is an approach which ends with a DH of 200ft or less. It would be true to say that this would normally be a 3D approach.

It would always be a 3D approach as all of the 2D-only approaches have system minima of 250’ or more.

(And a particular precision approach can have a minima higher than 200’, but the system minima would be 200 or less.)