View Full Version : A320 Go Around / Missed Approach
The question is related missed approach track on A320 family
1. When the missed approach track (in dashes) disappears from ND ?
Does it happen over threshold of selected RW ? But I saw that the track disappeared just before treshold and one time I saw it is still on ND when I had main landing gear already on ground.
2. and what should happen if you fly in NAV and then LEVEL OFF the plane just before land (above 400 feets), without applying TOGA, will it fly the missed approach track ?
Simulator says it will but I wonder the real plane could'nt do
3. What happen if we overfly the runway threshold in LEVEL OFF on high altitude (above 400 feets). Does the missed approach track disappear in that case or remains in dashes ?
4. Does the behaviour vary depends on pin settings of the aircraft ?
I need that to clarify the applicability of new SOP in topic of GO.AROUND procedure developed by one operator as it looks like a bit complex.
Wander
22nd Jan 2006, 19:01
In terms of when it is and isn't displayed I'm not sure. Suffice to say that if the Go around is in the MCDU then under the right circumstances it will be flown!
If you do a standard GA ie to TOGA and then push the HDG knob for managed NAV you'll fly the GA in NAV.
I don't think you could level the a/c on short finals and continue in NAV?
Certainly there is one anomolly which is in the FCOM 4 stating that if you overfly the destination (<7miles) the destination will be sequenced like any other waypoint but you'll lose the active flightplan!! It's happened! Out of interest, that's the logic that sequences the MCDU waypoints when you've taken the a/c into HDG........as long as the waypoints are <7nm away!
In terms of when it is and isn't displayed I'm not sure. Suffice to say that if the Go around is in the MCDU then under the right circumstances it will be flown!
If you do a standard GA ie to TOGA and then push the HDG knob for managed NAV you'll fly the GA in NAV.
Yes, and A320s (I guess new) do it for you once TOGA is applyed
I don't think you could level the a/c on short finals and continue in NAV?
I did on sim. It flyes the mssied approach in NAV, but if you did not activate NAV before the threshold it wont be activated even pushing HDG, but displayed in dashes on ND and NAV is armed but not activated.
Certainly there is one anomolly which is in the FCOM 4 stating that if you overfly the destination (<7miles) the destination will be sequenced like any other waypoint but you'll lose the active flightplan!! It's happened! Out of interest, that's the logic that sequences the MCDU waypoints when you've taken the a/c into HDG........as long as the waypoints are <7nm away!
Yes, I mentioned something like that but did not get it fully when and how it happens.
What could be the test plan to check it on sim so I could check this on next session I'll have soon ?
The main question is "Is there a difference between sim and the real plane behaviour" or in another words, can I trust sim in the missed approach sequence. Or maybe it depends on company pin programming for aircrafts. Does it affect this.
Wander
23rd Jan 2006, 10:16
I've been told that as the Bus uses computers to do all it's calculations then the simulators use the same boxes, ie FACs ELACs etc so should be the same!!
There are variations with company pin programming but I personally don't think it would be to do with this, more often auto height call outs etc.
Good luck!
I've been told that as the Bus uses computers to do all it's calculations then the simulators use the same boxes, ie FACs ELACs etc so should be the same!!
Yes, I know that, but not for all functions.
Will make more tests on sim then.
There are variations with company pin programming but I personally don't think it would be to do with this, more often auto height call outs etc.
Good luck!
The main question is QFE pin programming. It affects lot of functions.
But actually, on sim I can turn it off and then on and check what changes
blck,
The sim response depends on how the sim is 'hosted'. On some sims as 'Wander' has correctly stated, the sim has a/c computer components which are fed main computer generated data for airspeed, etc to enable said ELACs, MCDUs etc to work properly. However in some other sims (CAE produced a few to my knowledge) there are no a/c components just lots of rewritten software code to simulate what will happen in the a/c. The first sort of sim is called 'black box' and the latter 'grey box'. You must find out what type of sim it is to ensure what you are testing would be absolutely reporoducd in the a/c. Blackbox could generally be relied upon in the tests you describe. I have had the scenario you are worried about in the a/c for real and the flight plan is lost once the threshold has been overflown if TOGA has not been engaged at some point before hand. Note though that this will only happen if the flight plan is sequencing normally. :ok:
blck,
reporoducd in the a/c. Blackbox could generally be relied upon in the tests you describe. I have had the scenario you are worried about in the a/c for real and the flight plan is lost once the threshold has been overflown if TOGA has not been engaged at some point before hand. Note though that this will only happen if the flight plan is sequencing normally. :ok:
Actually all of them more or less are "simulators" :) but some computers and components used are real ones (MCDU, ELAC, FCU, FAC....) with simulated signals or it is fully simulated by one central computer. So it is very hard to define if it behaves like real A320 plane based only on the information.