A320 Autopilot engagement in alternate law
 

Does anyone out there have a reference for criteria allowing autopilot engagement in alternate law?

Many thanks, alteburger

Hi Alteburger,

FCOM 1.27.30 Flight Control Laws Reconfiguration shows the "AP Lost" region.

Thank you very much for that. I was hunting around that chapter, but our FCOM doesn't include the AP lost boxes. Have found an online version that does though...!

Alteburger

If AP engages, you can use it.

If you use it, keep it On until fully configured (CONF 3 gear down) and stabilized. Then it will be perfectly trimmed before you disconnect and go DIRECT LAW

Hi MB2002,
I hear crews briefing / doing this a frequently in the Sim.
That's another opportunity to practice manually trimming lost again.

Trimming Nightmare
 

Its hare to comprehend how you can trim when there are no stick forces for you to trim out. It's no wonder no one wants to try it. :ugh:

The question came to mind with the intention of a) making use of any autopilot capability to reduce workload during initial approach and, if an autopilot is available with the aircraft remaining in alternate law, whether there is a possibility of LVP capability (Cat 2). It appears that SEC 1+2+3 failure is a case where the autopilot is available in alternate law but until I've had a look in the sim, I've no idea whether that is possible. FCOM suggests it might be...

If you holding a stick position out of neutral to maintain a particular flight path, then you need to trim. i.e. there are stick forces to trim out.

If there is no stick force required to maintain your flight path, then you don't need any trim. :hmm:

It can be done, but of course you trim the airplane, not the forces, which is annoying and frustrating, in the beggining. It takes a little practice, then it is easy, but usually with a lot of unelegant pitch oscillations as you release the sidestick to check if the trim input was good or not.
I wonder if FS geeks would trim it better the 320 in direct law than real 320 pilots, since that is the way a FS airplane is trimmed. However I have seen how FS geeks crash a real 737 simulator because they couldn't trim.

what autotrimming has got to do with autopilot's availability? autotrim is available in alternate law (with or without protection) irrespective of autopilot's availability... autotrim and autopilot have no relationship to each other :=