Go Back  PPRuNe Forums > Ground & Other Ops Forums > ATC Issues
Reload this Page >

RNAV (GNSS) approach

Wikiposts
Search
ATC Issues A place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.

RNAV (GNSS) approach

Thread Tools
 
Search this Thread
 
Old 30th Jul 2012, 14:30
  #1 (permalink)  
Thread Starter
 
Join Date: Jan 2011
Location: Norway
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
RNAV (GNSS) approach

Hi

More and more major airports offer RNAV approach in thier instrumental approach charts. ENGM is one of these airports offering RNAV (GNSS) RWY for 19 R. According to an email I received from ENGM airport staff (Avinor), RNAV (GNSS) RWY 19 R approach is not VNAV certified. The RNAV approach chart is allows LNAV only. No VNAV yet. How does pilots control vertical guidance/descent down to MAPt? I'm not thinking in terms of step down descent. Can this be done using (CDA) Continuous Descent Angle by V/S down to MAPt?

I refer to following RNAV (GNSS) RWY 19 chart, ENGM:

https://www.ippc.no/norway_aip/old/A...GM_5-13_en.pdf


Sincerely

geirha75
geirha75 is offline  
Old 31st Jul 2012, 22:58
  #2 (permalink)  
 
Join Date: Dec 2000
Location: Samsonite Avenue
Posts: 1,538
Likes: 0
Received 0 Likes on 0 Posts
In the chart you have shown, in absence of VNAV then one would revert to flying the descent profile after the FAF using V/S (or FPA if you can/wish) and aiming for a CDFA.

It's pretty straight forward stuff.

Hope that helps.
Mister Geezer is offline  
Old 3rd Aug 2012, 20:26
  #3 (permalink)  
Sir George Cayley
Guest
 
Posts: n/a
Like any other non precision approach it's up to you to manage your descent profile.

With step down fixes one could be tempted into dive and drive, but constructing a descent profile based on a constant rate is safer.

If you have a WAAS enabled receiver then you'll see a form of vertical guidance derived from EGNOS, but a word of caution it won't be a true APV unless AVINOR recode the chart to include the vertical element.

SGC
 
Old 3rd Aug 2012, 22:42
  #4 (permalink)  
 
Join Date: Dec 2001
Location: Somewhere over the rainbow
Posts: 234
Likes: 0
Received 0 Likes on 0 Posts
Geirha75,

The approach is an LNAV only approach (as you can see on the chart), but that does not necessarily mean that VNAV cannot be used to fly it. The difference between LNAV/VNAV and LNAV Only is that the lnav/vnav will generally have lower minimas, and vnav must be used.

LNAV only does not prohibit the use of vnav (if it will comply with all parts of the approach), it simply does not require it, or offer the lower minima associated with it.

Certainly most of the GNSS approaches done down in this part of the world are LNAV Only, but they are still coded in the FMC database to allow VNAV to operate correctly.

So, the answer is yes, this would be flown as a constant descent - either using V/S as you suggest, or in VNAV if the approach was coded correctly in the FMC (which it most likely is).
A Comfy Chair is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.