Originally Posted by
rjtjrt
Morno.
I admit I am completely unqualified, but I have always wondered if ‘what’s it doing now” goes through crew mind, then getting it into Alternate Law, or Direct Law if possible, would at least put pilot back in charge.
I have been reluctant to ask this given my lack of real knowledge.
I ask what’s it doing now every single day
. However if I’m starting to say “WTF is it doing now?!?!”, then yes, by turning 2 ADR’s off, it puts it into alternate law and nearly all your normal protections are turned off. It puts the pilot mostly back in charge of the thing and should act only from inputs from the pilot.
The safety in turning off the ADR’s, is they’re reversible. So if you want to venture down the trouble shooting path and restore some normality to the system, it’s only the press of a button. The aircraft only needs 2 ADR’s to restore normal law.
I’m not type rated on the 330, only the 320, but essentially they are mostly the same. Perhaps the 330 is just slightly different in its flight control computers (PRIMS?), being a bit newer than the 320.
On the 320, and I assume it’s the same on the 330, Direct Law only occurs when you have selected gear down. So it’s normally only in those last few minutes of flight. And it’s a pain in the ass (in the sim at least) to fly, because the deflection of the flight controls is directly correlated to the control input from the side stick (it’s been a while since I’ve read this, so excuse me if it’s incorrect. Might be time to refresh my knowledge). Unlike Normal and Alternate Law, which still goes through the computers and deflects the controls an appropriate amount to meet the demand that we input through the side stick. So it will do it smoother and better. Unfortunately the side stick has zero connection to any flight control system, only a computer. So we have no feel at all.
When everything is running swimmingly, the Airbus is easy and quite nice to fly. When it starts going bad, it’s a pain in the ass. Almost as if Airbus couldn’t work out a better way to deal with abnormal situations, so it’s like a bunch of problems and checklists stacked on top of one another. Unlike the apparently easier way that Boeing has done it, whereby you have a problem, you run a checklist that deals with the situation from start to finish.