Airbus FBW
 

Can anybody explain the main difference between Alternate and Abnormal Alternate Law from the pilot's view while operating the airplane?
In case the fly-by-wire system is downgraded to Alternate/Abnormal Alternate or Direct Law is the autopilot available?
Thanks

Hi conch!

I'm not a pilot, so I can't give you a "real" insight. But I have a nice Link to a site which contains a pretty good description of all the different laws and their consequences on flying the bus. Just look here.

greetz, Niki

You can almost always use the AP and if it doesn't work you'll know. Under reduced system ops, you'll be using the AP down to 500' only anyway.

Abnormal Law is another name for Alternate Law.

Basically you get: NORMAL, ALTERNATE, DIRECT (LAW).

Within ALTERNATE law there are some sub-laws with reduced protections (low/high speed stabilities) and some without protections.

You'll also always get a reversion to DIRECT law when L/G is selected down (except with Abnormal Pitch Law).

Thanks for the explanations and the link Niki. I know it already. Just needed some more clarification yet.
Conch