Alternate law Airbus 320
 

Is it possible to perform auto land in alternate law , when you have all three SEC’s inop. In order to avoid disconnection of autopilot and reverting to direct law ?

Do a belly landing.

Note:If SEC 1+2+3 fail, the LGCIU information can no longer be sent to the ELAC. For the activation of DIRECT law, the ELAC uses the condition “slats and flaps in CONF 2” instead of “landing gear down”.

If I recall, yes you can auto land the A320 with all SECs inop...

From the MEL ENTRIES a paragraph at the end of each SEC failure (i.e. Sec 1, 2,or 3) basically says if the other two fail Autoland is not permitted.
Maximum landing capability is CAT1

ref MEL 27-94-01A, 02A and 03A

The A320 is definitely capable of auto landing with all SECs inop. Here I am talking systemwise. However, regulation wise it is not permitted...
regarding the "CAT 1 only" indication on FMA, this doesn't always mean that the plane is unable for auto land....it means that AFS is no longer fail passive/operative...
Thanks

I don't think this true....
With all SECs failure, the LGCIUs can still supply ELACs with gear info...
The scenario you are talking about occurs when both LGCIUs fail. In this case the AFS uses SFCCs to switch to Direct Law ..

https://cimg9.ibsrv.net/gimg/pprune....cefff189b.jpeg
The fcom I looked at for this failure shows Cat 3 dual inop on the status page which means that Cat 3 single would still be available.

No! LGCIUsv don't supply the ELACs in this case. It's flap2 that signals direct law. It's clearly given in FCOM ABN procedures.

Handsome Goafer :ok:
Right at the bottom of the Operational Procedure for each SEC is the magical line Cat 1 only. Hidden where most normal humans don't go in flight (unless they are REALLY bored).
Strange it's not listed in the required equipment in the Ops section of the QRH given it is a definite requirement and the prohibition is really buried.