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Copper.

RNAV approach types.

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Pulling my hair out trying to figure out the RNAV paradigm and its organisation. Grrr! Can anyone outline for me, ALL the different types of RNAV approaches, prefereably with a reference to the info.

 

The best I could come up with was <see web adress below>. Is this complete and correct? Are there any other 'RNAV Specifications'? I thought RNP was an RNAV sub-specification!?

 

 

http://filgapp.ineco.es/filgapp/showImg/ac662ecf-dd4f-4c45-bafe-ccfa2fc92ef4

 

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I don't know what you are after, if you are looking for some engineering specifications or some very legalistic FAA's documents about certification standards for different levels of RNAV then good luck, search on your own. But from pilot's (user's) point of view the situation is not that complicated when you are asking about RNAV approaches - there are 2 major groups: RNAV(GPS) and RNAV(RNP) - these are labels you see at the header of approach charts at least in the US. Of course, again from pilot's perspective, RNAV(GPS) can then be subdivided into precision and non-precision approaches, some of the acronyms here are: LNAV, LNAV/VNAV, LP and LPV - these are types of approaches though they often share the same approach chart. There is also another kind of RNAV approach which in the US is designated as GLS, however you won't see RNAV label here though it is in fact an RNAV-like approach. If you download free FAA's "Instrument Procedures Handbook" (a sizable well illustrated pdf document) then it talks about all these approaches in great detail - from pilot's perspective.

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Google and search on PPRUNE thats what i'm doing! Type in RNAV App PPRUNE you'll get loads to look through ;) i'm in the same boat is you lol

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Pulling my hair out trying to figure out the RNAV paradigm and its organisation. Grrr! Can anyone outline for me, ALL the different types of RNAV approaches, prefereably with a reference to the info.

 

You're making it more difficult than it really needs to be, honestly. Don't look too closely. Remain on a higher level to understand all of it. An ILS approach is an ILS approach. Most are CAT-I (which is the default), while others are CAT-II and CAT-III. Depending on the field/approach, they will have different minimums and requirements. RNAV approaches are similar. Some are RNP, some aren't; some are GPS, some aren't (though most are, now).

 

Trying to trace down all the various types of RNAV approaches is a lesson in futility. You'll learn virtually nothing from it simply by burying yourself in too much information. They're all flown in pretty much the same way. There's no sense in trying to track it all down.

 

 

 


Is this complete and correct?

 

Always check your domains when searching. Note the .es, so it's not FAA-specific, though I'm not sure what you're going for. Remember that aviation is handled slightly differently in each region.

 

 

 


Are there any other 'RNAV Specifications'?

 

What are you looking for, exactly? (Moreover - and not to sound dismissive - what does it matter?)

 

 

 


I thought RNP was an RNAV sub-specification!?

 

In the United States, it's treated as such, for the most part.

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Thanks Michal! The 'pilot's (user's) point of view', as you put it, is indeed what I'm looking for. I am merely trying to arrange all the different RNAV approach types into a chart, similar to the graphic from the link above.

Believe you me, I have been trawling my heart out! Although the Internet has a plethora of explanations of what each RNAV approach type is (which, from observation, can differ from state to state) few, or none give a broad view of RNAV approach types, and how they are arranged.

Take the above linked graphic as an example. It segregates approach types into two main groups... 'RNAV Specifications' (with it's approach types listed in the box), and 'RNP Specifications' (with it's approach types listed in the box).

This brings me to ask, from people who know what they're talking about, why the graphic shows RNAV and RNP as being two seperate entities.

My understanding was that RNP fell under the RNAV specification, and not it's own entity, as graphically portrayed.

Driver170 - thanks. I've trawled through there, amongst some other deep and dark places (ICAO/IATA/FAA/Various Regulators and Airline PBN Manuals, handbooks, pdf/ppt presentations etc). The most useful info I found was from a user called 'Reynoldsno1'... Who asserts:

There are 4 basic types of RNAV procedures available:
VOR/DME
DME/DME
GNSS
RNP (Required Navigation Performance)

The 1st three specify the source of navigation data to be used - the last specifies the accuracy to be achieved, and doesn't care how you do it - therefore allowing the full capabilities of the aircraft to be untilised. Any of the 1st three can be assigned an RNP value.

That, believe it or not, is the best text that I could find, that makes an attempt to arrange RNAV approach types.

Kyle. 

 

 


What are you looking for, exactly?
Ultimately, im looking for a list. A list of approaches that fall under RNAV.

 

 

 


(Moreover - and not to sound dismissive - what does it matter?)
It matters to me, only because I am clueless on the subject (even more than I thought).

 

When I came across this http://filgapp.ineco.es/filgapp/showImg/ac662ecf-dd4f-4c45-bafe-ccfa2fc92ef4 picture, I very nearly fell off my chair! I always thought that RNP fell under RNAV, but this picture (and the very many others like it), split the two - the pictures make it RNAV, and RNP respectively.

 

... I'm digressing.

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Hi!

 

When you say RMP, it's radio navigation precesion. But doesn't it use GPS? What is the difference?

 

What does it do to be an RNAV approach? The plane is still using GPS....so what makes the difference? It uses GPS for an VOR approach. It uses GPS for an RNAV approach. What makes the RNAV approach more precise?

 

What is LPV? What is the difference between LPV approach and RNAV approach?

 

Thanks

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The differences between rnav and rnp is the level of precision and how it is flown. Compared with the rnav, the rnp has lower minimuns. The rnp can also be flown with guidance to touchdown. With the rnav, we have to turn off the flight directors descending through mda to the runway. If we didn't we will see the fd trying to guide us onto the grass. With the rnp, the fd cues will take us all the way to the touchdown zone.

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When I came across this http://filgapp.ineco...fe-ccfa2fc92ef4 picture, I very nearly fell off my chair!

Why do you assume this is even correct? Or complete? Or have any value to a pilot?

You can find plenty of stuff on the internet - many misleading or outright wrong or bizarre.

I gave you a great resource directly from FAA, for pilots, well written, very extensive, illustrated, sorry I can't do more.

On one side you say you are trying to get it from pilot's point of view on the other you are looking for some 'charts'

that have no real value to a pilot.

 

scandinavian13 gave you a good advice - you have to operate on much higher level or you will get lost in useless data

that you don't even know how to interpret.

 

What is the difference between LPV approach and RNAV approach?

It is like asking what's the difference between an apple and a fruit.

LPV is one of RNAV approaches.

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Michael - it appears the chart was correct. It was my understanding of what the chart was trying to reflect that was the major problem.

 

As far as having taken your advice on board, I had already downloaded the 'Instrument Procedures Handbook' from the FAA, to my ipad. I outlined the fact (broadly), not to you, but to Driver170. My apologies.

 

 


I've trawled through there, amongst some other deep and dark places (ICAO/IATA/FAA/Various Regulators and Airline PBN Manuals, handbooks, pdf/ppt presentations etc).

 

Thanks Kevin! Your comment is also taken on-board.

 

AF330, I would love to answer your questions, but my understanding is very, very basic. I'll allow others to answer your questions.


The question I SHOULD have raised, "What are the different types of RNAV approaches?".

 

So to answer this question as best as I can -

 

There are 3 types of RNAV approaches:

- 2D RNAV - Horizontal plane guidance only (LNAV)

- 3D RNAV - Horizontal and Vertical guidance (LNAV + VNAV or V/S)

- 4D RNAV - Horizontal and Vertical guidance (LNAV + VNAV or V/S) with a timing function (the FMC's RTA function).

 

RNP APCH, RNP AR, APV, GNSS etc all fall into one of these categories? I guess that's the best I'll ever get.

 

 

As far as this http://filgapp.ineco.es/filgapp/showImg/ac662ecf-dd4f-4c45-bafe-ccfa2fc92ef4 goes... Further research shows that I should have researched the definition of 'Navigation Specification'. I now appreciate what this chart is showing which is the PBN concept (not an overview of RNAV in general... IDIOT!!!).

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Thanks michal!

 

So we use GPS for a LPV, a RNAV, a VOR.....etc.

Why is RNAV considered as precesion?

With RMP, LPV....etc. we still use GPS! What makes the difference?

 

Thanks

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- 4D RNAV - Horizontal and Vertical guidance (LNAV + VNAV or V/S) with a timing function.

this is your own invention.

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this is your own invention.

Not so, old boy.

 

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750022064.pdf

 

ICAO Document 9613 excerpt -

1.6 FUTURE DEVELOPMENTS

1.6.1 Currently, PBN aims to harmonise longitudinal and lateral performance requirements (i.e. 2D) for both RNAV and RNP specifications and in the future, a progression is expected to include 4D trajectory-based operations.
 
 
Have you anything to the contrary?

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Have you anything to the contrary?

Yes, I do. It is the future, not current operations. Any current 4D operations do NOT include the approach phase (say after the GS/GP intercept). You are confusing approach with arrival. Also your own documents say this is very limited right now, experimental, for example has no application when traffic is high. By the way you show the paper from NASA Ames - this is exactly where I worked in the last 10 yrs doing air traffic management studies. I don't know these 2 gentlemen but I knew quite a few who worked on 4D problems. Your paper is very old, 1975 - a lot changed since then, 4D research advanced. You could find for example scientific papers by Richard Mogford (current NASA Ames) on the topic of 4D and generic airspace, I collaborated with him. For enroute operations and arrivals at TRACON area 4D is very close but even this is still done on limited basis.

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I'm in awe of your achievement... I truely am.

 

The placement of 4D in my comment was more to acknowledge it's existence and applicability to RNAV, rather than to imply that the concept is matured and in practice - this I did, for the sake of completeness, and to solicit responses, much like yours, in order to progress my understanding on the subject of RNAV.

 

Further, and I hope you don't take offense, your post have an underlying tone of mild condescension. I am simply trying to grow my knowledge. I do not presume to be an SME on RNAV - RNP - or aviation in general. When you come out with one liners like "this is your own invention"... Well what can I say. This entire comment wouldn't have to exist, if, in the first place you kindly explained ypur views pertaining to 4D RNAV.

 

Nonetheless, the leads you have given me are gratefully received. I intend to add it to the must read list! (Which grows by the hour).

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Basically, an RNAV waypoint is more precise because FMGS has got a more precise position of the waypoint? Thanks

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Feel as though i've answered my own question, and solved my own predicament. Here is an RNAV chart*, styled the way I wanted it. It is a derivative of the Navigation Specifications chart I posted in my original post.

 

http://tinypic.com/r/2ajcldh/8

 

*Subject to review due error on my part.

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Further, and I hope you don't take offense, your post have an underlying tone of mild condescension.

I am sorry if I came across too harshly, I did not mean disrespect.

I am glad you found what you were looking for but clearly it has nothing to do with what we would call pilot's perspective.

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