Dual RA Fault A320
 

Hi all, question regarding a Dual RA fault on the A320 as there seems to be contradictory information in the FCOM / FCTM.

If gear is extended and the AP is on, will the AP disconnect and go straight to direct law?
OR
Will the AP remain engaged after gear down and subsequently remain in normal law until you disconnected the autopilot?

Many thanks!

Who cares, chances of this actually hapening are extremely rare. If it does, just fly the aircraft that you have, and don't try to rememeber which configuration every failure will leave you with.

God forbid someone try and develop their knowledge by asking a sensible question in the appropriate forum... Absolutely nonsense response.

To answer the question. If you review the control law reconfiguration list in the systems pages, it confirms that L/G down is the cue for the aircraft to enter direct law, and hence the autopilot, if on, would disconnect at that point.

Cheers

thanks for your reply, I was unsure as after seeing a video of a crew run this failure in the simulator, it looks like it didn’t actually go into direct law until ap off despite gear down.


I suppose probably a simualtor inaccuracy?

The flippancy of the reply was probably uncalled for, but some of the sentiment is valid. By all means, a thirst for knowledge is great and should be welcomed, but memorising all the nuances of failures in detail - especially in a sim - is not always a great idea and can lead you down the wrong path. Your real life failure will never be the same as what you get in the sim.
There's a reason today that much training is around pilot competencies, with relatively few rote learned events. If you get the competencies right, you can better deal with whatever weird wacky and wonderful things the aircraft throws at you at any time of day and night.

I don't really see the issue here.
The question simply formed after indulging in some of the manuals.
There's plenty of other threads in this forum which ask techy questions.


I asked it in the appropriate form, if you don't like it then simply scroll. :ugh:

Maybe reread my reply carefully. I don't have an issue with the question. You appear to have the wrong end of the horse.

apologises. I replied to the wrong post.

Interesting, I'd not seen the video. Can only go off what the manuals say having not experienced it for real. The prompt for direct law does appear to be gear down, however there is some contradictory information in the FCTM. Barring real life experience of the failure, it is impossible to actually confirm it.

Without RA you would not get any of the landing modes (LAND, FLARE), or even be able to select APPR mode, meaning an FPA descent. So you would have to disconnect at some point anyway. But it seems odd to engineer it that way round.

Completely agree. Effective competencies ensure good handling of failures, not complete knowledge of all of them. However, this is a forum for technical questions and I think the rudeness was completely unwarranted for a valid question which now also has me curious!

The video is not of an A320. Possibly the A330 has a different logic?

Hi, "THis DVD has been produced by Qatar Airways Airbus DVD flight operation 340/330".

A330 is different. On approach, flare law becomes active when the L/G is selected down and provided AP is disconnected.

it says this in the 320 fctm too under dual ra failure

wording is

• DIRECT LAW becomes active when the L/G is selected down and provided AP is disconnected. At this point, "USE MAN PITCH TRIM" is displayed on the PFD
  

Yep, but the DUAL RA AIRBUS PDP Presentation actually reports that upon L/G extension the AP will disconnect. Which is what actually happens. 😐

thank you!

It also depends on what software/hardware standard you may have. Your company’s manuals for the correct/reference MSN will be the most accurate. Videos from other operators will likely have options/software/hardware standards very different to yours.

They are good for the general gist of a drill but you must reference your own manuals to figure out exactly what’s fitted to your fleet.

​​​​​​​Thanks, ChatGPT.

Hi all,
Any time the plane swithces to Direct Law the AP will self disconnect. So, in dual RA fault the switch to Direct law occurs at L/G extension wich will disconnect the AP immediately and the App & landing are done manually...

You are on final app with AP ON and single RA failure. Now if you loose second RA will the AP disconnect and transitioning Direct law?

Hello Vilas, long time no see....
From memory the answer is yes..
When you loose the second RA on final APP, the Direct Law activates and that will trip the AP....
you can not have the AP while in Direct Law.
you can have the AP while in Normal Law and in ALTN law (certain failures)....