A320 Single Engine TOGA Selection

[Scapa]

I have looked through recent threads and cant find the answer to my question so here goes:

-----------------------------------------------------------------
From FCOM 1 1.22.30

GO AROUND (GA)
Go-around mode combines the speed reference system (SRS) vertical mode with the GA
TRK lateral mode.
ENGAGEMENT CONDITIONS
Setting at least one thrust lever to the TOGA detent engages both SRS/GA TRK modes,
if :
– The flaps lever is at least in position 1, and
– The aircraft is in flight, or
– The aircraft has been on the ground for less than 30 seconds (AP disengages and can
be re-engaged five seconds after lift-off).
– FD bars are automatically restored in SRS/GA TRK modes.
If FPV/FPD was previously selected, it reverts to FD bars.
The FMA displays “SRS” and “GA TRK” in green.
----------------------------------------------------------------------


So with an engine failure after take off you would normally have FMA's: Flex SRS NAV, should you need TOGA power the FMA's go to: TOGA SRS NAV why does the GA mode not engage as the above engagement conditions are all met?

I know the correct behavior is not to engage GA TRK but cant find the FCOM ref to back it up. All i can find seems to suggest SRS GA TRK should engage.

[TopBunk]

Forgive me, as it's several years since I flew the A320, but as you have just taken off, you haven't Gone Around, if you see what I mean, so the Take Off modes atill apply and all you have done is increased power to TO (not GA).

I am probably 100% wrong, in which case please feel free to disregard my mumblings.

[John Citizen]

Excellent question about something which also confused me.

I found the answer here on pprune a few years ago after I posted the topic but I can not find it anymore. Maybe you can find it.

Basically I was told not to look at the engagement conditions of the Go Around Mode (which we both did) but to look at at the disengagement conditions for the SRS mode, which are :

SRS (SPEED REFERENCE SYSTEM) :

– Disengagement conditions
The SRS mode disengages :
• Automatically, at the acceleration altitude (ACC ALT), or if ALT* or ALT CST* mode engages
(above 400 feet RA).
• If the crew engages another vertical mode.
• If the crew selects a speed while in SRS mode : SRS reverts to OP CLB mode, and a triple-click
aural warning is heard.
Note : In Engine Out conditions, the SRS mode does not automatically disengage at EO ACC ALT.
Refer to Engine Out procedures.

Therefore if you apply TOGA whilst in SRS, the SRS mode will NOT disengage, therefore the Go Around mode will not ENGAGE !!

I think this is the answer.

Just another Airbus trap/Airbus manual trap which also caught me out.

You think there would be a note saying something along these lines under Go Around Engagement Mode conditions. Being Airbus, you have look for the answer under a different topic nothing to do with the Go Around Mode.

[Neupielot]

Could it be also you need to activate the approach phase to be able to engage GA phase? Just guessing.:O

[mcdhu]

No, because if you select TOGA while in level acceleration OEI (to speed things up a bit), it will go "MAN TOGA/SRS/GA TRK" - much to some folks' surprise.

The way out of it is to 'Push to level Off' again to get "VS 0".

mcdhu

[flyer146]

Hello,

You are in take off mode FMGS wise. Setting TOGA in this phase will not trigger the go-around mode of the fmgs. Imagine, you need toga during your t/o or initial climb for whatever reason, and the thing switching to go-around modes...("GO TRK ..."). Not nice engineers thought. Critical phase, pilot asks thrust, give him that and keep the other modes.

Setting toga during the t/o phase will just give you MAN TOGA/ A THR blue, other mode/logics/activation will remain.

As soon as another vertical mode engages (by the FMGS or by yourself), then the FMGS switches to CLB phase. I.e you push to level off for OEI cleanup : the system goes into CLB phase ! (remember target speed auto jumps to clb speed even OEI).
Then it's another story and you will get GO-AROUND mode activation of FMGS if conditions described above are met... only if you activate TOGA AFTER the clb phase has activated.
Very unusual case, less critical phase, balance between too complex software / + required response in thrust will still be achieved.

Same thing one engine out.

The system is built taking into consideration the possible need of TOGA during the FMGS t/o phase hence not activating "surprising modes".
But, as in any other aircraft, if you start playing "the more clever pilot" and I am saying this without arrogance, we all try that from time to time... (like setting toga during OEI accel level) then you might get surprises !

Enjoy,

Flyer146

[toby320]

Hello, flyer146is right, the answer is easy you are on t/o mode remember the fmgs works in 8 fases preflight, t/o, climb, cruise, descent, approach, GO ARROUND, and done, so srs during t/o mode works in one way and during approach in other.

I hope this helps.

Regards

Toby:ok:

[Gutter Airways]

From FCOM 1 1.22.30

GO AROUND (GA)
Go-around mode combines the speed reference system (SRS) vertical mode with the GA
TRK lateral mode.
ENGAGEMENT CONDITIONS
Setting at least one thrust lever to the TOGA detent engages both SRS/GA TRK modes,
if :
– The flaps lever is at least in position 1, and
– The aircraft is in flight, or
– The aircraft has been on the ground for less than 30 seconds (AP disengages and can
be re-engaged five seconds after lift-off).
– FD bars are automatically restored in SRS/GA TRK modes.
If FPV/FPD was previously selected, it reverts to FD bars.
The FMA displays “SRS” and “GA TRK” in green.


If aircraft is on the ground for more than 30 seconds, then SRS engages, provided V2 is inserted in FMGC and at least Flap 1 selected.

See FCOM 1.22.30 P47 for SRS engagement conditions.

[John Citizen]

Imagine, you need toga during your... initial climb for whatever reason, and the thing switching to go-around modes...("GO TRK ..."). Not nice engineers thought.

Not nice but it does happen. :eek:

If you set TOGA during the initial climb after take-off (still with some flap out) (OPEN CLIMB) it will give you the go around mode, as I discovered by surprise once, however the FMGS was still in the CLIMB phase :eek:

Why does setting TOGA during the "initial climb" phase give you the Go Around if you are still in the "CLIMB phase". You might say you get the Go Around mode because you meet all the preconditions for engagement (as listed above), but why would you ever want the Go Around mode during the Climb phase, if its all to do with phase ?

Why would the FMGS ever be designed so that it will go into the GO AROUND mode during the CLIMB phase ?

Why would you ever need the GO AROUND mode ever during the CLIMB phase ?

If its all to with the phase of flight, then shouldn't the Go Around mode only be available only during the APPROACH (and DESCENT) phase (which sounds logical), and not during the CLIMB phase as well.

If GO AROUND mode is not available during the takeoff phase, then it should not also be available during the climb phase as well, but it is.

[flyer146]

Hello John,

You describe the logic I wrote above. Difference between TO phase and CLIMB phase of fmgs.
Indeed it has all to do with fmgs phase but you also need + other conditions as described above !
For example you need the conf at or above 1. In fact the flap LEVER must be at or above 1 position, the system doesn't look at real pos of flaps.

I understand what you mean, but in fact only during a very short period before the flap lever being moved to 0 in clb phase could you be into a "surprising" mode if you would select TOGA. Seldom requirement but it could happen.
After that flap retraction phase, TOGA will not trigger go around phase.

It certainly is not IDEAL and that is what you underline, but as with all softwares, there is certainly a balance between IDEAL and costs + possible other interactions we don't even think about in other phases... Don't forget also that it must be build "fail-safe" and that is where this kind of "easy" logic programming may play a role. Who knows ? (airbus engineering/test pilots do certainly know why...).

The phase you describe is less "critical" and give you normally more room to react. FMA check will attract your attention and if it's not what you need, why just not disconnect the A/P-F/D-A/THR and fly conventional ? I recognize we should be more trained for these possible events... costs...costs....:bored:

See u,

Flyer146

[Right Way Up]

John,

I had exactly that happen after a Toga takeoff. I was just reducing to Clb power when we hit some shear and my instinctive reaction was to go back to the Toga detent which then made my life a little more interesting especially as there was a pretty sharp turn coming up. I learnt a little more about the aircraft that day.

[DERG]

If the machine decides that the input is incorrect but you KNOW it is correct...well...why not..

Just have a BIG RED push "auto stop" button?

Then you can continue with flying the machine manually?

Have I missed the obvious here?

[One Outsider]

Have I missed the obvious here? Yes, plus shown a lack of basic knowledge of aircraft and auto flight systems.

[DERG]

That's a hell of an arrogant answer. I can see why airbus moans about basic flying skills being lost.

My basic understanding is fine but I remain puzzelled at the way the machine is autonomous.

Maybe all this started when they got rid of flight engineers?

I will ask again..why is there not an EMEGENCY OFF switch for the FMS?

No need to be rude. Most machines have manual overides.

[TyroPicard]

DERG .. I will ask again..why is there not an EMEGENCY OFF switch for the FMS?
AP OFF
FD OFF
A/THR OFF if you wish
It is that simple.

[CaptainProp]

This is why we READ the FMAs!! If you don't see/read what you like and expect to see - go "selected-selected" and read again. Still dont like what you see? A/P OFF, FD OFF and fly the thing like we used to do with aircraft :} and then have your colleague re-engage the automatics again! :ok:

CP

[CaptainProp]

Tyro beat me to it... :ok:

[DERG]

THANK GOD someones knows what the F they are doing.

[One Outsider]

That's a hell of an arrogant answer. No it's not. It's a straight answer. My basic understanding is fine If it was, you would not be asking the questions you do. I remain puzzelled at the way the machine is autonomous I am sure you do, but again the lack of a basic understanding seems to be what's keeping you puzzled. I will ask again..why is there not an EMEGENCY OFF switch for the FMS?Why would anyone want to switch off the FMS? Do you even know what a FMS is or what it comprises? THANK GOD someones knows what the F they are doing.Yes, perhaps one day you will too.

[DERG]

Why are you scared of posters asking questions? I have been barred off this site before and I am sure if you can make a good case to the administrators they may ban me again.

On the other hand the administrators need to sell advertising. It would be easy to make this site an exclusive club but I doubt if the advertisers would be happy. In the mean time as long as I can log onto this site I will.

[Wingswinger]

To return to the thread:

but why would you ever want the Go Around mode during the Climb phase, if its all to do with phase ?

Observed in a simulator recently during an EFAV1 exercise:

After controlling the aircraft through the engine failure (without selecting TOGA) and before engaging AP the captain calls "Pull heading".

The co-pilot pulls altitude instead so the aircraft goes into OPEN CLIMB.

Suddenly no SRS and no V2 indication on PFD.

Captain engages AP, sets TOGA (SRS/GATRK) and pulls heading himself. Fixed.


Q.E.D.

[320 driver]

Wingswinger

You have hit the nail on the head. Its not really to do with phase.

You start a take-off and if you take TOGA during that take-off you dont get GA modes. If you end the take-off by selecting different vertical mode or by passing into climb phase (just a trigger condition) then the GA mode is available from then on.

[John Citizen]

Can anyone please quote any references in the manuals regarding this matter to support the other theories out there.

In theory, you should be able to read the manual, (also understand it and learn it) then fly the aircraft without discovering any new surprises :eek:

If do you discover any surprises (as a few of us did), you should be able to go back to manual and discover why.

I am not disagreeing with anyone but where does it say it in the manuals anything about the "phase" of flight.

Is this in some large yet to be published / secret Airbus manual :confused:

Although I suppose takeoff and climb whilst still in SRS is a phase of flight. If you will not get GO around mode until SRS is disengaged (as I said), therefore you could say you will not get GO around mode whilst still in the takeoff phase. Pretty much the same thing I suppose (disengage SRS after takeoff / outside the takeoff phase).

[Right Way Up]

320 Driver,

I am fairly sure that by going into OP CLB the takeoff phase ends and you are now in the CLIMB phase (albeit much earlier than usual). This would backup the claim that it phase related.

[TyroPicard]

John C
No big secret... Flight phases are listed in FCOM 4.02.20 .. p11. (Always takes me ages to find that page....)

There is no phase called "initial climb".

Switching from TO phase to CLB happens automatically at ACC ALT, or by engagement of another vertical mode before reaching ACC ALT. Selection of TOGA following EFTO does not change the vertical mode so the flight phase remains TO.

In that situation you want to remain in NAV or HDG, and not change to GA TRK.

you could say you will not get GO around mode whilst still in the takeoff phaseTrue - if you need TOGA for some reason during a FLEX T/O you do not want G/A TRK to engage.

[John Citizen]

John C
No big secret... Flight phases are listed in FCOM 4.02.20 .. p11.

Thanks for the reference. I just had a look but it still seems like a secret to me. :confused: Nowhere on this page does it say anything along the lines regarding the Go around mode and the fact that "it is inhibited/not available during the takeoff phase." :confused:


There is no phase called "initial climb".



I did not ever say there was.

I said "....during initial climb....still in climb phase".

I (and others here) use the word "initial" to specify that first small (initial) part of the climb phase that you enter and still have some flap out !

Even though it's all one phase, they way the aircraft will behave when selecting TOGA depends whether or not you have flaps out. This part of climb with flap out I refer to as the "intial climb" to further clarify what I mean, as this is the way you enter the climb phase.

[TyroPicard]

Hi John
Nowhere on this page does it say anything along the lines regarding the Go around mode and the fact that "it is inhibited/not available during the takeoff phase."And nor should it - the page is about FMGS flight phases, not about AP/FD modes.
I did not ever say there was. In that case I must have misunderstood this sentence...
Why does setting TOGA during the "initial climb" phase give you the Go Around if you are still in the "CLIMB phase". I tend to be pedantic when using Airbus technical language and assume everyone else is trying to be as accurate...
You actually answered the query well in Post 3 but we seem to have got confused along the way ..
To check your understanding of "phases" and "modes" try this poser...

On base leg, flying level, FMA's say SPD ALT HDG, Flap 0, you activate the approach.
You then select TOGA.
1. What is the FMGS flight phase?
2. Will the FMA change, if so to what?

[flyer146]

Indeed, it is worth on a normal flight to observe the FMGS phase switching to start with.
If you select the PERF page, you will see the big title at the top of this page = FMGS phase. Certain logics and subsequent mode activation (as toga selection) are related to fmgs phase.

Now, more complex, same question as Tyro above post, but with flaps 1 ?
...here there is a trap or 2 answers possible I believe...

We can discuss it further after your posts.

Flyer146

[John Citizen]

TP, I apologise.

I actually did write "initial climb phase", but I also wrote "initial climb" phase give you the Go Around if you are still in the "CLIMB phase".

What I meant to write was during the initial part of the climb phase.

On base leg, flying level, FMA's say SPD ALT HDG, Flap 0, you activate the approach.
You then select TOGA.
1. What is the FMGS flight phase?
2. Will the FMA change, if so to what?

1. Approach phase ? :confused:
2. MAN TOGA, (ALT HDG A/THR blue) ? :confused:

[flyer146]

1. Approach phase ?
2. MAN TOGA, (ALT HDG A/THR blue) ?

Yes, correct to me !

Now, this one :

Same question but you have FLAPS 1.
There is a trap here...

[John Citizen]

I believe :
"MAN TOGA, SRS, GA TRK, A/THR (blue)" ? :confused:

or could this also be possible ?

MAN TOGA, ALT, GA TRK (A/THR blue) ?????? :confused:

[TyroPicard]

John C

No apology necessary!
1. Approach phase ? http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif
2. MAN TOGA, (ALT HDG A/THR blue) ? http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif2 is correct - just the A/THR changes.

But..... FMGS flight phase will switch from APPROACH to GO-AROUND - see FCOM 4.02.20 p11 for "switching conditions to next phase" column.
So.. we have the AP/FD flying S&L but the FMGS in a go-around phase.

Conversely, in the "initial" part of the climb with FLAP lever still at 1 or more, selection of TOGA will put the AP/FD into SRS G/A TRK (a "common mode" i.e. both lateral and vertical modes - you always get both together) but the FMGS will remain in the CLIMB phase because the switching condition is "reaching cruise FL".

Simplze, no?

And flyer146 - back to ground school!

[flyer146]

2 is correct - just the A/THR changes.

But..... FMGS flight phase will switch from APPROACH to GO-AROUND - see FCOM 4.02.20 p11 for "switching conditions to next phase" column.
So.. we have the AP/FD flying S&L but the FMGS in a go-around phase.

Conversely, in the "initial" part of the climb with FLAP lever still at 1 or more, selection of TOGA will put the AP/FD into SRS G/A TRK (a "common mode" i.e. both lateral and vertical modes - you always get both together) but the FMGS will remain in the CLIMB phase because the switching condition is "reaching cruise FL".

Simplze, no?

And flyer146 - back to ground school!

:\ oops indeed ! (ground school is CBT, so I won't learn much there :} )

But Tyro, you said : TOGA will put the AP/FD into SRS G/A TRK (a "common mode" i.e. both lateral and vertical modes - you always get both together).
:= not true during T/O phase ! So you don't ALWAYS get both together...

-Now another one :

1. APP phase activated, flaps at 0
2. Altitude selector set to a different altitude than actual one.
3. TOGA selection

FMA ? FMGS mode ?

-And another one :

4. APP phase activated, flaps at 1
5. Altitude selector set to a different altitude than actual one
6. TOGA selection below GA acceleration altitude
7. TOGA selection above GA acceleration altitude

FMA ? FMGS mode ?

:E

[Bus Driver Man]

4. APP phase activated, flaps at 1
5. Altitude selector set to a different altitude than actual one
6. TOGA selection below GA acceleration altitude
Altitude selector will be set to a different altitude than the actual most of the time during approach. E.g. on the ILS with the G/A altitude selected.
I don't think the altitude selection has any influence on what FMA modes will engage.
IMO the standard MAN TOGA - SRS - GA TRACK

4. APP phase activated, flaps at 1
5. Altitude selector set to a different altitude than actual one
7. TOGA selection above GA acceleration altitudeI suppose the FMA will indicate the flashing LVR CLB immidiately after selecting TOGA.

[TyroPicard]

flyer146
not true during T/O phase ! So you don't ALWAYS get both together...If you read the whole sentence you will see the FMGS is in CLIMB phase, not T/O. I was trying to illustrate to JohnC that the AP/FD and FMGS can appear to think along different lines....
And my "always" means that for any common AP/FD mode you always get both the relevant lateral and vertical modes together.
Unless JohnC has more questions... too much thread drift for me. G'day.

[Upper Air]

There is, there is mate, yu would normally, auto pilot off and autothrottle disengage, you would then have manual control, its two moves - but not one universal button yet. If you want to disengage the `brain` of the system giving you indications on the Primary Flight Display (PFD) just select FD (Flight Director) off, and then you can fly the aircraft raw - like a little aeroplane (weighing in at 60 tonnes or more).

All of the right hand column of the FMA will be blank.

[Upper Air]

Very nice answer - you are getting there - stick with it. .

[jorel]

Been searching for an answer to a recent situation thought I was going to find it.... But flyer146 question went unanswered..


So could anyone confirm what the Fma will read after selecting Toga in the following conditions

F2
Gear down
V/s hdg... On the Fma and selected speed ( just lost the ils signal )
Approach phase activated
above the acceleration altitude
At 2000 ft on the approach.
Go around altitude set on the FCU

I wasn't expecting the Fma to read what it did.... So I'm thinking I must have done something else..

Any answers much appreciated

[Microburst2002]

jorel
it will show MAN TOGA/SRS/GA TRK.
anyway I don't understand what does accel alt has to do during approach
perhaps you should rephrase the question?


Eveveryone else:
The key, as someone said before, is in the SRS mode:

there are two different SRS modes (with different guidance). One for take off, and one for GA.
The modes are related to flight phase because of the speed targets. In take off, the speed target is V2 plus 10 or pitch 17,5º. in GA, the target is VAPP or actual speed upon mode activation, which ever is greater.

Only during take off phase the target speed is V2 related. As long as you are in take off phase, SRS will always be take off SRS with V2 as the reference. Once you change phase, however, speed target changes and go around SRS will activate when levers advanced (when conditions are met) and the reference will be VAPP (if in approach phase) or actual speed.

[jorel]

Thanks microburst

In looking for my answer in FCOM's I came up with the following

Disengagement of SRS Mode happens as you pass through the accel alt (ref 1.22.30 p47)

If this is the case will SRS engage by selecting TOGA above accel alt (2 eng)

If what you say is correct, then the aircraft would remain in SRS until Alt* or alt cst or another vertical mode selected,or climb power selected,as acceleration altitude (2 engines case) condition would not be met.

Thanks for the clarification