A320 CAT 3 single, cat 2 & 1 autoland question
 

Hi guys,

Forgive me, I have looked all over pprune for a specific answer to this question but cannot find one. New to the 320. Help would be appreciated.

Can the 320 still autoland in cat 3 single, cat 2 or cat 1 conditions or does the autopilot have to be disconnected at the DH in all three cases? I am totally lost with this.

Many thanks..

FCOM-LIM-AFS

Thanks. I have looked at that and found the section. I'm still a bit confused though.

Could you, for example, test the Autoland capability of the aircraft at a runway that is only CAT1? For training purposes on a clear day?

Sorry, I know these questions sound daft but would appreciate any help or explanation.

Are you referring to weather conditions? The autoland system doesn't know what the weather is, just it's own technical status as displayed in the landing capability part of the FMA.

From a technical point of view, if there is a technical downgrade of landing capability, then the automatic landing capability is as per the FCOM-LIM-AFS section as stated above. If the aircraft says Cat 1 in the FMA it can't autoland and the lowest minima for an approach would be ILS Cat 1 minima. However, if the aircraft is fully serviceable and the weather is Cat 1 conditions, the aircraft can still autoland. It doesn't know the weather, company SOPs or ILS category.

With EASA you can only autoland on a runway that has minima lower than CAT1 published (eg CAT2/3). If lvp’s aren't in force then you need to be careful as the localiser and glideslope aren’t protected. Also you can’t come below Cat1 minima unless you are visual without lvp’s. The FMA must be displaying an autoland category (eg cat 2/3).

If you meet all the above criteria then you can autoland to your hearts content, just be ready to intervene if it goes wrong.

ATB.

LD

Have you got a reference for this? Of course we all know the limitation to have at least CAT2 landing capability showing in the FMA for an autoland, but will the aircraft technically be able to land with CAT1 in the FMA? FCOM is, as per usual, not very clear. The aircraft itself seems to go through all the correct mode changes (LAND, FLARE, RETARD) with CAT1 displayed.

Guess that ain't so.

It's not daft, but it IS dependent on your airline's procedures. If it is not expressly prohibited, I don't see why not. In our case, even if the runway is Cat 3, when we do one for currency, we advise ATC and they will usually say "Roger. Be advised, ILS critical area is NOT protected". That means we have to be especially diligent, since the signal might do something wonky.

Your Airbus is able to perform AUTOLAND on CATl runways, as long as your FMA shows at least CAT2 capability.
Be aware of some limitations, especially your terrain profile ahead of the threshold and your beam is not protected and may fluctuate.
Your minimum stays CATI, so you need to see the runway at that point.
Check your QNH for required equipment for CAT2 and CAT3 operations, so your FMA will engage.
Plus your company needs to allow you to do it, check your OM-A.
But yes, technically it is possible.

Additional, if I get you right:
Look for APPROCH STRATEGY in the FCTM:

Autoland CAT1 possible with precautions; CAT2 recommended, but manual landing possible; CAT3 single or dual mandatory.

The aircraft will perform an autoland as long at least one autopilot is engaged and either CAT1, 2 or 3 along with G/S and LOC are annunciated on the FMA.

The limitation for autopilot engagement without at least CAT2 displayed is not below 160ft but the autopilot will remain engaged and go on to perform an autoland with only CAT1 displayed. Worth bearing in mind if your back was really against the wall.