A320/1 Autoland (Systems Sequencing)

[Bernoulli]

I'm due soon for my six monthly sim check and I've noticed over the years that with each check the instructors seem to love digging a little deeper into 'what goes on behind the scenes' on an auto land approach. Each time the (different) instructor seems to have at their disposal a newly discovered fact about one of the systems and how it behaves during the approach and landing. It's like a sort of arms race that, to be honest, I'm losing.

No doubt the information is out there in the FCOMs but our company documents seem to be in a state of constant flux. There's probably little new stuff in it all but the buggers keep moving it around. No sooner have you found something and bookmarked it that it's vanished! There's a bit here and a bit there but all scattered.

Do any of you kind souls out there have a document that gives an overview of the behaviour and timings (with ref to rad alt) of the various systems on the A320/1 that draws it all together in one place? I'm sure such material will be of interest to the wider Airbus fraternity.

All pointers gratefully received.

[Goldenrivett]

Hi Bernoulli,

Like this?
CATIII.jpg

Ask your instructor why we wait until 350 feet agl before we check the ILS Course is correct on the PFD. Since the FMGC data is locked at 700 feet agl, wouldn't it be better to check it before then?

[Bernoulli]

Ahh, you're a kind person Goldenrivett. Much obliged.

I'll wait to see how the day shapes up before posing the question....

[Uplinker]

Hi Bernoulli.

Our SOPs used to be that on LOC* PF checked and announced 'LOC star, course set', but now we don't officially mention the course at all.

I used to think it was just me being thick, (it still might be), but thanks to the Airbus and EASA way of doing things, our manuals are really difficult to navigate through and find information.

Any subject we are told about seems to have between 3-7 separate references in the books. Why can't they group everything relating to each subject in one place :- how the system works, the SOPs, the task sharing, the calls, failure modes, diagrams, the limitations etc? So if one wanted to learn about something, everything would be in the one chapter.

Also, things are not explained very clearly. We get a huge thick pack about the next new thing, say, GNSS or FLS which seems baffling and complicated, but when you actually use the system on the line it is quite simple.

As you say, 'they' keep changing everything as well. So, sorry, I don't have the info you need, but at least I now know it is not just me being thick !

One thing you could try though is find an obscure fact deep in the manuals and casually drop it into the conversation. That might make the TRE think that you know or have read at least as much as they have and they might stop giving you such a hard time !

.

[Airmann]

Here's a question about an auto land that no one seems able to answer. In an emergency, if you have to put the aircraft down on a field which is not in the box and you don't have time to create the runway, only to insert the ILS frequency and course in RAD NAV will the aircraft be capable of an auto land? If not at what height will the auto pilot disconnect?

[Goldenrivett]

Hi Airmann,

I would say it would do an autoland.

The list of "Required Equipment for CAT2 and CAT3" (QRH) doesn't include a requirement for the ILS to be loaded using using the data base.

However I never imagined that a bit of software which got very upset if a fix radial crossed the final approach just before the runway would cause the FMGCs to crash either. (old OEB169)

[sonicbum]

Once the ILS is tuned, it is tuned regardless if that was automatically or by manual insertion of course and frequency. You are then able to use all the associated functions of the Autoflight system. Make sure that within 15 NM from the airfield you deselect TERR in order to avoid the EGPWS nuisances.

[Max Angle]

No need to deselect the terrain function, the EGPWS system does not use FMGS airfield data, it has its own internal worldwide database that contains every hard runway longer than 3500ft.

You will only get LAND mode (without which there will be no autoland) if G/S mode is showing on the FMA. This can only be engaged by pressing the APP p/b and will only engage if an ILS approach is present in the active flight plan. As long as you have that, as far as I know, the frequency can be manually changed and you will still get G/S then LAND annunciated and an autoland will follow. You are going to get an ILS/RWY mismatch message but I don't think that will prevent G/S engagement.

With no ILS in the flight plan you will only have HDG and V/S available to follow the ILS and no autoland.

[vilas]

Max Angle
The FCOM does not support what you say.


GENERAL


The ILSapproach mode includes the following modes:


VERTICAL MODE LATERAL MODE



G/S* (capture) LOC* (capture)
G/S (track) LOC (track)




COMMON MODES:
LAND - FLARE - ROLL OUT

The sequencingof these modes is automatic once the flight crew has pushed the APPR pb and theconditions for engagement are met.

SELECTION

The ILSapproach is selected when the APPR pb of the FCU is pressed and:


‐An ILS approach or a runway only or no approach is inserted in the FlightManagement flight plan (ARRIVAL page), and an ILS frequency is set in on theMCDU, or


‐Both radio management panels are set to NAV and each one has the ILS frequencyand course set in.


DSC-22_30-80-30-10P 2/18


FCOM ←A → 27MAY2014

[CaptainMongo]

Vilas is correct, as an added note for those using Thales FMGC's, the below is from Thales New Pilots Guide Release 1A:

"Notes - At 700FT RA : Approach Data are locked, i.e. ILS/MLS/GLS freq & course are frozen in the receiver, when in APPR mode (LOC & G/S armed or engaged) with at least one AP/FD engaged. Any entry via MCDU or RMP does not affect the receiver."


There was an accident regarding this where the crew hard tuned an ILS freq for use during a departure and never cleared it (our SOP is to clear the RAD/NAV page of pilot tuned NAVAIDS at 18k) On approach they couldn't figure out why they couldn't get the FMGC loaded ILS to work. The FMGC will not overwrite pilot loaded NAV aids. (I can't find the report of that incident, if anybody recalls it, I would appreciate a link - thanks)

[Bernoulli]

Hello Max Angle.

A few months back I landed on the new runway down at Hurghada which was not at the time in the EGPWS database although it was to be found in the MCDU. Following Company advice (in very small print it has to be said) I switched off the TERR function of the EGPWS and landed without incident. Following us in to land was a colleague who hadn't spotted the advice and whilst coming in to land had had the 'full monty' of "Terrain Terrain" etc. It was CAVOK so he landed anyway.

I guess that's an indication at least that the EGPWS is a self contained system with its own database and probably isn't too worried about ILS signals when considering runways and terrain (ILS glideslope a being a different function).

BTW, where did the link to Goldenrivett's diagram go from the response to my opening post?

[mcdhu]

Hi Bernoulli,

Ask him

1. What would happen if RA1 or 2 failed at 80' RA and what the PF should do about it - if anything?

OR

2. Given that that there is no PM call of "No Flare", how much chance is there on a Cat3b/Dual approach in 75m RVR, of avoiding a heavy landing if there is no flare and is there any way of avoiding a 700fpm anding?

Pse post the responses.

Have a good check,

Mcdhu

[Speedwinner]

Can anybody answer the questions of mcdhu? I can't :-(

[FlightDetent]

My company operates LVOs i.a.w. the FCOM from manufacturer.
Thus, FLARE and ROLLOUT are called out by PM. THR IDLE is not.

I note with much interest the remark about non-existent "no flare" call. True, unlike for instance "no reverser", it is not in the FCOM. What is the PM then supposed to do if there is no flare mode engagement?

Interestingly, my first Airbus LVP course was in Toulouse and for sure I had been trained to announce NO FLARE if the FMA mode is not there by 35 ft. And it has been a check/pass-fail item on the several* operators' LVP curriculums, I had the pleasure to familiarize myself with.

*One operator prescribed "GO AROUND" call instead of "no flare" by PM.

Check Airman: For CAT IIIA I struggle to imagine how PF could effectively scan for outside reference and make the decision at 50 ft, and then come head down to verify FLARE mode engagement. Same for CAT II, actually. PM is head-down and thus FLARE is his responsibility to verify and then announce to PF to keep him in the loop.

[Check Airman]

Originally Posted by FlightDetent

My company operates LVOs i.a.w. the FCOM from manufacturer.
Thus, FLARE and ROLLOUT are called out by PM. THR IDLE is not.

I note with much interest the remark about non-existent "no flare" call. True, unlike for instance "no reverser", it is not in the FCOM. What is the PM then supposed to do if there is no flare mode engagement?

Interestingly, my first Airbus LVP course was in Toulouse and for sure I had been trained to announce NO FLARE if the FMA mode is not there by 35 ft. And it has been a check/pass-fail item on the several* operators' LVP curriculums, I had the pleasure to familiarize myself with.

*One operator prescribed "GO AROUND" call instead of "no flare" by PM.

Check Airman: For CAT IIIA I struggle to imagine how PF could effectively scan for outside reference and make the decision at 50 ft, and then come head down to verify FLARE mode engagement. Same for CAT II, actually. PM is head-down and thus FLARE is his responsibility to verify and then announce to PF to keep him in the loop.

I should probably not post when I'm tired. I completely misread the original post, then proceeded to post nonsense. My company has a "no flare" callout, which would trigger a GA.

[vilas]

CaptainMongo
It was Hermes airlines landing at Lyon resulting in an incident not an accident because of not clearing RAD NAV of manually tuned ILS at departure from Ajaccio. The link below:
https://www.bea.aero/docspa/2012/sx-...v120411.en.pdf

[Goldenrivett]

Check Airman: For CAT IIIA I struggle to imagine how PF could effectively scan for outside reference and make the decision at 50 ft, and then come head down to verify FLARE mode engagement. Same for CAT II, actually. PM is head-down and thus FLARE is his responsibility to verify and then announce to PF to keep him in the loop.

We don't have a "No Flare" call.

It is not necessary for PF to scan inside either. (S)He should hear "50, Flare, 30,20,10 Roll Out"
If "Flare" is missing by the time (s)he hears 30 then it is (her) his decision to take over manually or GA.

[seen_the_box]

2. Given that that there is no PM call of "No Flare", how much chance is there on a Cat3b/Dual approach in 75m RVR, of avoiding a heavy landing if there is no flare and is there anyway of avoiding a 700fpm anding?

The reason that "No Flare" isn't a call is that, according to Airbus Technical and Training, there is no failure case which would only lead to FLARE mode not engaging. In other words, if you have LAND by 350', you will always get FLARE, unless you have some sort of system failure in the intervening period, which would lead to a go around anyway (triple click, master caution, autoland light etc.) Therefore, "No Flare" would be a superfluous call.

Regarding the RA fault question: surely it depends "how" it fails. The autoland light will be activated if it fails in such a way that a >15' discrepancy exists between the two RAs, even if only momentarily, thereby mandating a go around in the absence of sufficient visual references.

[FlightDetent]

I think the last two posts complement each other rather well. Thanks for your inputs.

[Uplinker]

The reason that "No Flare" isn't a call is that, according to Airbus Technical and Training, there is no failure case which would only lead to FLARE mode not engaging. In other words, if you have LAND by 350', you will always get FLARE, unless you have some sort of system failure in the intervening period, which would lead to a go around anyway (triple click, master caution, autoland light etc.) Therefore, "No Flare" would be a superfluous call.

Learn something every day - Thank you STB. Why don't they teach us this stuff, so we would understand why we do it the way they say??

Although by the same logic, the "flare" call is also superfluous.

Since the other guy is looking out and therefore not looking at the RAD ALT display, how does he know that flare has not occurred at the correct height until it is too late? I think that in the absence of [FLARE] at 40-30', the call "go-around" from PNF would be far more useful - there is not enough time for PF to realise there was no flare call and react by disconnecting the A/P and manually flaring, without it getting very messy.

.