FCOM PRO-ABN-34-NAV ADR 1+2+3 FAULT

Under associated procedures. Nb. The Level 2 note only appears for the range of MSN described above.

L1 F/CTL ALTN LAW
(PROT LOST)
Note:
L2 When the aircraft is in clean configuration, the flight control law reverts to direct law.

Something to be wary of. Simulators (datapacks) have their own unique MSNs which may not correspond to any actual aircraft. Airbus no longer supply datapacks to tail numbers.

Specific FCOMs are supplied with these datapacks too.

Thanks Cripple,

I've found the same note for some of our MSNs now.
Very interesting and not widely understood.

Cripple
Got it. It is only for SIM std 1.8. I had seen it before but as Golden said didn't realise it's true meaning because in SIM session generally we do UAR after take off where flaps are always at Conf1 or 2. Also it immediately does not become clear that should you encounter UAR after retracting flaps or in clean configuration at altitude and switch off all ADRs it will transit to Direct law. I think Airbus should have explained it more in FCTM, especially because from FCOM as I quoted before, triple ADR doesn't transit to Direct Law but Alternate without protections. Another thing is std1.8 on ADRs do not process AoA input but IRs do that is why it asks you to put off all three ADRs while older ones without BUSS you got to keep one for stall warning. May be that has some connection and original and retrofitted systems may be behaving differently. Thanks anyway for the input it makes it so much clearer now.

No problem. It took me a while to find the answer. As you say, the FCTM could at least mention it!

FYI

We were told when the BUSS was initially implemented that direct law is active until flap extension, then Alternate until gear down.

The simulator was in alternate law but the instructors had the info at this time that it was a glitch according to FCOM.

After some research I realized that this was only applicable only to one of our MSN's, which in coincidence happened to be the MSN representing the simulator.

The latest FCOM has completely removed this and all msn's now are at alternate law until gear down of course.

The sim was correct...

As a matter of interest, airbus simulators no longer follow aircraft MSNs. They all follow a specific simulator MSN dependant upon standard and engine fit.

Yes, I meant the msn closer to the sim

Question for you gurus. For the newer aircraft that have the "BKUP SPD/ALT" buttons. We recently received an aircraft with these buttons installed; it is in the FCOM but not represented in our simulators.

How does this work exactly? According to the FCOM the captain or first officer can independently activate the BUSS on their respective PFD at any time by pressing this button, and it is reversible.

I assume that if you just reach down on a normal day and hit that button, the PFD simply displays the BUSS information in lieu of the normal (stilll functioning) airspeed and altitude tape, without affecting the flight control laws or ADRs in any way. Yes? No? What about the autoflight system? If for example AP1 is engaged and the captain decides to "see what that button does" does it kick the autoflight off, or does everything continue to function? FCOM PRO-ABN-NAV section references a couple of ECAMs the simply say "AP 1 (2).... DO NOT USE" which sort of sounds like they dont go away on their own.

Anyone actually used this thing yet?