Airbus FCU technique w/RNAV
Thread Starter
Joined: Jan 2022
Posts: 106
Likes: 5
From: Miami
Airbus FCU technique w/RNAV
Regarding RNAV approaches, what are you guys doing
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Joined: Jul 2006
Posts: 1,100
Likes: 111
From: Somewhere over the rainbow
We managed descent until FDP altitude. When FDP waypoints is the « to waypoints » we arm the approach. That’s Airbus SOP by FCOM. But some guys will arm it way earlier and it works just fine. But if too high on profile, I noticed it does some aggressive nose down inputs which can be problematic if you already have flaps.
Joined: Nov 2010
Posts: 1,167
Likes: 180
From: USA
Regarding RNAV approaches, what are you guys doing
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Joined: Feb 2009
Posts: 946
Likes: 445
From: Austria
Setting the FAF altitude on the FCU with altitude constraints on the way will work in principle when:
- flying a full procedure that comes with stepdown altitudes correctly coded in the database,
- flying in DES, not any selected mode.
However, bear in mind that ATC only sees Your FCU altitude and does not know whether or not You are going to keep the higher altitude constraints. There are airports where there is a major separation issue behind those: consider LLBGs RNAV Visual GAVRI 30 or the RNP X where You are to maintain 5000´until REBDO to keep clear of possible go arounds that will climb 4000´and cross below You and also 26 departures.
So I would strongly advise using either selected descent or, at the very least, keeping the FCU altitude synchronised with the currently cleared altitude. In LLBG, this is even a requirement.
- flying a full procedure that comes with stepdown altitudes correctly coded in the database,
- flying in DES, not any selected mode.
However, bear in mind that ATC only sees Your FCU altitude and does not know whether or not You are going to keep the higher altitude constraints. There are airports where there is a major separation issue behind those: consider LLBGs RNAV Visual GAVRI 30 or the RNP X where You are to maintain 5000´until REBDO to keep clear of possible go arounds that will climb 4000´and cross below You and also 26 departures.
So I would strongly advise using either selected descent or, at the very least, keeping the FCU altitude synchronised with the currently cleared altitude. In LLBG, this is even a requirement.
Joined: Dec 2013
Posts: 133
Likes: 72
From: Milan
When cleared for approach and flying a procedure with many intermediate step altitudes, I simply put the FDP (or FAP) altitude and fly descent mode. I think it’s the easiest and less workload required technique. Then inbound fdp (ie fdp to point) arm approach
Joined: Mar 2006
Posts: 2,633
Likes: 137
From: USA
However, bear in mind that ATC only sees Your FCU altitude and does not know whether or not You are going to keep the higher altitude constraints. There are airports where there is a major separation issue behind those: consider LLBGs RNAV Visual GAVRI 30 or the RNP X where You are to maintain 5000´until REBDO to keep clear of possible go arounds that will climb 4000´and cross below You and also 26 departures.
So I would strongly advise using either selected descent or, at the very least, keeping the FCU altitude synchronised with the currently cleared altitude. In LLBG, this is even a requirement.
So I would strongly advise using either selected descent or, at the very least, keeping the FCU altitude synchronised with the currently cleared altitude. In LLBG, this is even a requirement.
Joined: Feb 2009
Posts: 946
Likes: 445
From: Austria
Because only 99% of aircraft will comply. The remaining one will be on its way to a repetition of the Washington collision.
On a STAR and approach with multiple stepdown altitudes that a constant flow of arriving aircraft is fed into, it is simply not feasible to ask every aircraft about their intention to keep its upcoming altitude constraint. This would completely clog up the frequency. Instead, having aircraft show their next intended level off altitude via their FCU window and Mode S transponder is a low-workload method to ensure everyone has the right picture. If some traffic was to proceed to a waypoint with a constraint of 5000´+ while showing a FCU altitude of 2300´ already, questions will be asked - there might even be an automated altitude alert showing up on the controllers screen.
In some airspaces, managed descent is not the best of ideas.
On a STAR and approach with multiple stepdown altitudes that a constant flow of arriving aircraft is fed into, it is simply not feasible to ask every aircraft about their intention to keep its upcoming altitude constraint. This would completely clog up the frequency. Instead, having aircraft show their next intended level off altitude via their FCU window and Mode S transponder is a low-workload method to ensure everyone has the right picture. If some traffic was to proceed to a waypoint with a constraint of 5000´+ while showing a FCU altitude of 2300´ already, questions will be asked - there might even be an automated altitude alert showing up on the controllers screen.
In some airspaces, managed descent is not the best of ideas.
Eidolon
Joined: May 2001
Posts: 2,244
Likes: 62
From: Some hole
Regarding RNAV approaches, what are you guys doing
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Neither is correct.
if your aircraft has xLS, the arming conditions for the approach are the same as an iLS, and the missed approach altitude is set like an ILS with F-G/S * & F-LOC*. Procedural descents according to the chart are performed the same as a procedural ILS.
Without xLS, flying the bricks. Approach is armed when the TO waypoint in the FM shows the start of the coded descent, eg shows the start of the 3 degree descent after the waypoint. Should see a descent arrow at this waypoint. Pressing approach prior to this waypoint can result in altitude constraints not being followed.
Missed approach altitude set at FINAL APP.
Prior to pressing APPR, the lowest altitude on the procedure can be placed in the FCU, and DES used, this will ensure constraints are complied with.
Joined: Jan 2004
Posts: 3,246
Likes: 202
From: Here and there
Regarding RNAV approaches, what are you guys doing
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Prior Company, LCC all-Airbus operator (USA). Training department was basically "Airbus factory curriculum"
"Cleared for approach" (APPR is green/active in MCDU by now)
Push APPR pushbutton, arm the approach
Set "bottom altitude" FAF/FAP altitude in altitude window FCU
PUSH altitude knob
Set missed approach at FINAL APP
Current Company, mix of Boeing and Airbus
"Cleared for the approach"
Push APPR pushbutton, arm the approach
Do nothing else
Set missed approach altitude at FINAL APP
Both "work" but....
Thanks
Joined: Mar 2012
Posts: 2,605
Likes: 154
From: Having a margarita on the beach
Because only 99% of aircraft will comply. The remaining one will be on its way to a repetition of the Washington collision.
On a STAR and approach with multiple stepdown altitudes that a constant flow of arriving aircraft is fed into, it is simply not feasible to ask every aircraft about their intention to keep its upcoming altitude constraint. This would completely clog up the frequency. Instead, having aircraft show their next intended level off altitude via their FCU window and Mode S transponder is a low-workload method to ensure everyone has the right picture. If some traffic was to proceed to a waypoint with a constraint of 5000´+ while showing a FCU altitude of 2300´ already, questions will be asked - there might even be an automated altitude alert showing up on the controllers screen.
In some airspaces, managed descent is not the best of ideas.
On a STAR and approach with multiple stepdown altitudes that a constant flow of arriving aircraft is fed into, it is simply not feasible to ask every aircraft about their intention to keep its upcoming altitude constraint. This would completely clog up the frequency. Instead, having aircraft show their next intended level off altitude via their FCU window and Mode S transponder is a low-workload method to ensure everyone has the right picture. If some traffic was to proceed to a waypoint with a constraint of 5000´+ while showing a FCU altitude of 2300´ already, questions will be asked - there might even be an automated altitude alert showing up on the controllers screen.
In some airspaces, managed descent is not the best of ideas.
Joined: Jun 2025
Posts: 1
Likes: 0
From: Chile
I agree with setting the FCU lowest altitude and with the FDP as to waypoint arm de APP PB.
Few months ago I was looking where I can find that's necessary to put the lowest altitude on the FCU. Why I can't set the IAF or IF as the altitude. Or I'm wrong?
Regards!!
Few months ago I was looking where I can find that's necessary to put the lowest altitude on the FCU. Why I can't set the IAF or IF as the altitude. Or I'm wrong?
Regards!!
