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-   -   A320 interrupting the ILS (https://www.pprune.org/tech-log/621095-a320-interrupting-ils.html)

avieh7 2nd May 2019 08:17

A320 interrupting the ILS
 
will appreciate if one of you, A320 experienced Drivers, will tell me what’s happening when during an ILS (LOG, G/S engaged, and Alt is set to go around altitude) the Alt knob is being pushed..? (in terms of modes changes) and how to revert back to ILS...

sonicbum 2nd May 2019 08:54


Originally Posted by avieh7 (Post 10461116)
will appreciate if one of you, A320 experienced Drivers, will tell me what’s happening when during an ILS (LOG, G/S engaged, and Alt is set to go around altitude) the Alt knob is being pushed..? (in terms of modes changes) and how to revert back to ILS...

Nice one.

Above 400 ft RA :

DISENGAGEMENT CONDITIONS OF G/S ONLY

‐ The flight crew pulls out the V/S or FPA knob. LOC mode remains engaged, but G/S mode
disengages and V/S or FPA engages.
The flight crew pushes or pulls the ALT knob. LOC mode remains engaged, and the mode
selected by the flight crew engages, as a function of the FCU selected altitude.

BUT :

The descent mode is a managed mode that may be engaged during cruise. It can be armed or
engaged in descent and approach phases (except if the FCU selected altitude is higher than the
present aircraft altitude).

Throughout the years I have had a few trainees caught out of startle effect pulling the ALT knob when setting the (higher) GA altitude ending up in a cancelled approach (no big drama, lesson learnt I guess). Regarding the "pushing" I am not sure, as the aircraft is on the correct vertical profile (vertical deviation centred) but the GA altitude is (let's say) above Your current altitude so technically nothing should happen but let's see if someone has experienced it and can shed some light. I will be in the SIM in a few days anyway so will try it out (still not close enough to retirement to try it on the line).

pineteam 2nd May 2019 13:34

My guess is that nothing will happen if you are GS green and you push the ALT knob with GA ALT higher than your actual altitude passing. But I’m not 100% sure and no FCOM with me now. I would love to try it but I will be only flying on the 22. Vacation time. You can try it by quickly pushing the ALT p/b. If by any chance it starts to climb, quickly vertical zero, arm approach again, VS-1500. You will be on profile in no time.

vilas 2nd May 2019 13:38


[ Regarding the "pushing" I am not sure, as the aircraft is on the correct vertical profile (vertical deviation centred) but the GA altitude is (let's say) above Your current altitude so technically nothing should happen
Correct. Descent mode cannot engage unless FCU altitude is below the present altitude. In case after GS capture the OPCLB mode gets engaged then push VS and follow capturing GS from above procedure by setting a suitable VS like -1800.

sonicbum 2nd May 2019 13:49


Originally Posted by vilas (Post 10461313)
Correct. Descent mode cannot engage unless FCU altitude is below the present altitude. In case after GS capture the OPCLB mode gets engaged then push VS and follow capturing GS from above procedure by setting a suitable VS like -1800.

Have done both when it happened, went around or GS from above. It depends on many factors.

vilas 2nd May 2019 13:53

As far CLB mode getting engaged after pushing it will not.

The CLB mode can be engaged, if the following conditions are all met:
‐ The aircraft has been in flight for more than 5 s
‐ The selected FCU level is above the present aircraft level
‐ The descent, approach, or go-around phase is not active
‐ NAV mode is engaged
‐ Glideslope (G/S) mode is not engaged.

sonicbum 2nd May 2019 14:28


Originally Posted by vilas (Post 10461321)
As far CLB mode getting engaged after pushing it will not.

Thanks, I believe we can almost 100% say that nothing will happen in relation to the OPs question.

avieh7 2nd May 2019 15:24

Thanks for all the answers..
so it can only be interrupted by pulling for open climb.. and the recover to g/s again is by arming the approach again and pulling the v/s knob for around -1500 to intersect from above..

Check Airman 4th May 2019 14:50


Originally Posted by Citation2 (Post 10462408)
If you inadvertently pulled open climb while setting go around altitude , one technique that works well is:

-push to level off and simultaneously ask for gear down.
- select a V/S to intercept from above and arm approach.
-if you were in selected speed , managed speed without delay.

it works like a charm

...or press the 2 little red buttons. There's one close to each thumb ;)

vilas 4th May 2019 17:11


.or press the 2 little red buttons. There's one close to each thumb
How will that help? With FD in open climb? Good knowledge of automation is necessary. Sochi crash because he disconnected and then got disoriented.

FlightDetent 4th May 2019 17:55

He means each button in a different hand. :) and FDs = OFF.

I like Citation's solution too. If it is a quick reflex motion, such as the one for ALT* with excessive V/S, it would be elegant.

sabenaboy 4th May 2019 19:03


Originally Posted by pineteam (Post 10461311)
You can try it by quickly pushing the ALT p/b. If by any chance it starts to climb, quickly vertical zero, arm approach again, VS-1500. You will be on profile in no time.


Originally Posted by Citation2
If you inadvertently pulled open climb while setting go around altitude , one technique that works well is:

-push to level off and simultaneously ask for gear down.
- select a V/S to intercept from above and arm approach.
-if you were in selected speed , managed speed without delay.

it works like a charm

I'm with Check Airman on this one. :D Use the red buttons near both thumbs, F/D's off (Bird on if you want) and fly the ILS. Works like a charm, except for children of the magenta line.

pineteam 4th May 2019 19:33


Originally Posted by sabenaboy (Post 10462981)
I'm with Check Airman on this one. :D Use the red buttons near both thumbs, F/D's off (Bird on if you want) and fly the ILS. Works like a charm, except for children of the magenta line.

This is an obvious easy solution, AP and Fd off and fly raw data. Except like you say for the children of the magenta line Lol.
But if you inadvertently select open climb, unless you are too slow to react or things getting ugly you don’t need to hand fly. And I’m a big fan of raw data. But in that case, you just have to press 2 buttons and you are back to normal. Easy peasy. = )



wiedehopf 4th May 2019 20:43

There are approaches where FD or AP is mandated due to parallel approaches for example.

Check Airman 5th May 2019 01:21


Originally Posted by wiedehopf (Post 10463044)
There are approaches where FD or AP is mandated due to parallel approaches for example.

I'm sure even in this example, you'll be just fine hand flying raw data while the other person reconfigures everything.

Check Airman 5th May 2019 01:23


Originally Posted by vilas (Post 10462904)
How will that help? With FD in open climb? Good knowledge of automation is necessary. Sochi crash because he disconnected and then got disoriented.

After pressing the buttons, the FD mode doesn't matter.

vilas 5th May 2019 10:07


After pressing the buttons, the FD mode doesn't matter.
While I have no doubt about your ability to fly raw data ILS, the correct procedure to use the two buttons on each side is to use them with two more buttons on the FCU i.e. the FDs and switch them off when you don't intend to use them. It's not smart to leave them in open climb mode while descending or vice versa. It can confuse the other guy. Knowing automation well does not indicate you cannot hand fly. In adverse environmental conditions disconnecting the AP at the drop of a hat can and has created problems.

Check Airman 5th May 2019 11:38


Originally Posted by vilas (Post 10463416)
While I have no doubt about your ability to fly raw data ILS, the correct procedure to use the two buttons on each side is to use them with two more buttons on the FCU i.e. the FDs and switch them off when you don't intend to use them. It's not smart to leave them in open climb mode while descending or vice versa. It can confuse the other guy. Knowing automation well does not indicate you cannot hand fly. In adverse environmental conditions disconnecting the AP at the drop of a hat can and has created problems.

I don't disagree at all Vilas. Just making the point that if the AT is off, there's no inherent danger in going against the FD. In this particular scenario, I'd obviously prefer the FD off.

Check Airman 5th May 2019 11:52


Originally Posted by Citation2 (Post 10463221)
From FCTM: Airbus Golden Rule :Take action if things do not go as expected . The PF should change the level of automation:from managed guidance to selected guidance or from selected guidance to manual flight »

Straight to manual flight is not wrong but you have to be able to manage the workload and the startle factor.

History showed that uncontained startled factor in an unexpected situation along with autopilot disconnection often exacerbated an already difficult situation which could have been sorted by keeping automation.

You have to differentiate between a planned raw data approach and an unexpected auto flight behavior due to technical or pilot lapse or error.

and by the way I forgot : « use the appropriate level of automation at all times »

i suspect this comes down to a difference in operational philosophy. Here, most people would rather just disconnect the AP than go through the interventions above, elegant as they may be.

FlightDetent 5th May 2019 19:03

Check, we do not disagree with your solution either.

Yet please observe: The task-sharing for CJ2's method:

either PF/PNF -> announce <explanative of choice>
PF -> move finger by 2 inches and push, turn then. Simultaneously call GEAR DOWN
PM - set L/G lever down
PF - read FMA "VS -2000"

Done in under two seconds, situation contained and the aircraft state / modes are exactly where they had been planned to be. No mental shift for the crew and all text-book callouts and cross-cockpit verifications.

Exactly ONE (admittable double) action of FCU, ONE command, and read of ONE commanded mode change. The full take-over and disconnect has more moves / tasks by order of magnitude.

Besides, personally, I'd go
- AP off and push to keep the nose from rising
- retard the TL's back to around 1/3 travel (a lot) but keeping ATHR on, even if limited
- call FD's off, then TL's to CLB again or ATHR off.
(8 "events" if I calculate correctly)


Feel invited to write yours, from where I am it looks like you are in CL detent with man thrust. :-) Google speed tape confusion, and it has killed more than few times already.


On the topic of "children of magenta", a term which is these days overwhelmingly used as a snotty remark to throw insults around by people who did not put the effort in to understand the message of that lecture ...
... waste of time.

sabenaboy 5th May 2019 20:47


Originally Posted by FlightDetent (Post 10463783)
On the topic of "children of magenta", a term which is these days overwhelmingly used as a snotty remark to throw insults around by people who did not put the effort in to understand the message of that lecture ...
... waste of time.

I'm not sure if that remark was ment as an insult to me or not?

I'm sure that the 'elegant' solutions that are proposed here will work nicely, but the problems with the solutions that are proposed here appear not to be very instinctive but something that has to be thought about before it occurs.
There's one solution that will ALLWAYS work in ANY SITUATION where the automatics don't do what you expect them to do: switch them off, (A/P, F/D and A/T), put the aircraft in the position you want it to be (attitude, bank...) and adjust the thrust as necessary.Then and only THEN, you could re-engage the automatics as desired/needed.
This is a simple solution, that will work in any situation where the automatics don't 'behave'. Every pilot worthy of that title should be able to do that instinctively. Sadly, I realize, that's not always the case anymore.
I do not blame the pilots personally, but rather the companies they fly for and their training departments.

It is not my intention to make 'snotty remarks to throw insults' but to emphasize again that we are seeing more and more accidents happen due to the lack of basic flying skills and that needs to be addressed.

If you search my previous posts, you will find that 'basic manual flying skills' is is one of my favorite subjects, I like to post about.
Look at these if you want to:

Airbus Official Urges Major Pilot Training Changes
Some more links to posts about manual flying skills.
My view on basic flying skills.

vilas 6th May 2019 04:41


Works like a charm, except for children of the magenta line.
If a child of magenta managed the situation keeping the AP on he deserves credit. And if the experienced guy had to disconnect to manage the situation because of his insufficient knowledge of automation then he deserves censure not the child.

FlightDetent 6th May 2019 05:18

sabenaboy Thanks for the reaction. Kindly understand that the first version I typed read "exclusively" and I changed that to "overwhelmingly" after having scrolled up to double check and seeing your name.

I think that your and vilas' comments:

There's one solution that will ALLWAYS work in ANY SITUATION where the automatics don't do what you expect them to do: switch them off, (A/P, F/D and A/T), put the aircraft in the position you want it to be (attitude, bank...) and adjust the thrust as necessary. Then and only THEN, you could re-engage the automatics as desired/needed. This is a simple solution, that will work in any situation where the automatics don't 'behave'.

Knowing automation well does not indicate you cannot hand fly. In adverse environmental conditions disconnecting the AP at the drop of a hat can and has created problems.
outline the course boundaries perfectly. Calling "CoM", which is our board's version of the Hitler argument, is foul play in this game.

Whilst I reworded to allow specifically for your personal expertise, post #13 - written the way it is - gets a yellow card. Not because of it's merit that a pilot is one who does not fear to disconnect the automatics and knows well how to handle the A/C manually with style, but because of the argument's shape.

vilas 7th May 2019 03:12


This is a simple solution, that will work in any situation where the automatics don't 'behave'. Every pilot worthy of that title should be able to do that instinctively. Sadly, I realize, that's not always the case anymore
A pilot of a modern commercial jet is a complete package that includes the basic handling skills and also mandatorily adequate knowledge of it's automation. Inadequate skill at either end will make the pilot unworthy. While it's beyond doubt that pilots must aquire and maintain basic flying skills it cannot be converted into a crusade against automation. Automated flights may be less exciting but they make flying safer, less tiresome and extract more out of the available airspace and they're here to stay.

compressor stall 7th May 2019 11:46

well here’s how it goes wrong...
 
They pulled Open Climb on the ILS...

https://www.atsb.gov.au/media/577600...-034_final.pdf

Not a terribly brilliant report with some holes but it still covers the basics.

vilas 7th May 2019 14:07


Originally Posted by compressor stall (Post 10465338)
They pulled Open Climb on the ILS...

https://www.atsb.gov.au/media/577600...-034_final.pdf

Not a terribly brilliant report with some holes but it still covers the basics.

Interesting! the cockpit gradient was not shallow but reverse inclined. The captain not doing his PM job adequately out of respect.


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