Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

A320 All ADRs Are Wrong during unreliable speed

Tech Log The very best in practical technical discussion on the web

A320 All ADRs Are Wrong during unreliable speed

Old 24th Apr 2017, 22:47
  #21 (permalink)  
 
Join Date: Nov 1999
Location: UK
Posts: 1,177
When switching off two ADRs, you might want to leave PF's side one on.
Uplinker is offline  
Old 25th Apr 2017, 05:29
  #22 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting home
Age: 41
Posts: 2,556
ADRallwrong..PNG

Back to BEFORE post one before anybody finds out about this little chat of ours?
FlightDetent is offline  
Old 25th Apr 2017, 16:43
  #23 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,298
Normally it blends inputs from rudder pedals and the two dedicated tillers to command nose-wheel deflections. The ratio is dependent on airspeed.

If ADR 3 might have an unreliability the system hasn't detected (which I think is what we're assuming), and you left it on, it seems like you could still end up with something like a large NWS deflection early in a cross-wind landing (because the ADR thought the airspeed was low when it wasn't).
This is not factual because it is ground speed and not airspeed.
DSC-32-20-10 P 1/4
The BSCU transforms these orders into nose wheel steering angle. That angle has the following limits, which depend on ground speed and the origin of the orders.


vilas is offline  
Old 25th Apr 2017, 17:07
  #24 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,298
Uplinker
When switching off two ADRs, you might want to leave PF's side one on.
Why would anyone do that? Because PF habitually will believe in the wrong speed displayed and could get in trouble.
vilas is offline  
Old 25th Apr 2017, 17:34
  #25 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,298
topla abicim
During Un.Speed ADR Cx Proc you aware that your all adr are wrong
You have to turn 2 of them off (IF THERE IS NO BUSS)
My question is which one should remain?
As I know,
If you keep ADR1 you can maintain XPDR/ATC1 and GPWS
If you keep ADR2 you can maintain XPDR2 and NW/STR
If you keep ADR3 you can use you LDG GEAR otherwise GRAVITY
The whole discussion has gone on the wrong track. Your first condition was all ADRs are wrong. So you keep one only for stall warning. After that you are treating that one as good one. No this one is also bad so the three options you mention are really not available. You will land not as dual ADR fail procedure but triple ADR fail. So the gear is lowered by gravity anyway. GPWS if available with faulty ADR1 you will use it only to your peril. And triple ADR fail procedure doesn't say NW steering as inop. You will have to depressurise the aircraft manually because faulty ADR is not going to do it.
vilas is offline  
Old 25th Apr 2017, 18:28
  #26 (permalink)  
 
Join Date: Nov 2006
Location: Top Bunk
Posts: 204
Try thinking outside the box. GPS ground speed is available on pretty much all hulls after MSN 800ish.
Would have saved AF 447 if it was used or recognised
Fly the plane. Keep the nerdy stuff on the ground!
45989 is offline  
Old 29th Apr 2017, 06:25
  #27 (permalink)  
 
Join Date: Nov 1999
Location: UK
Posts: 1,177
Originally Posted by vilas View Post
Uplinker
Why would anyone do that? Because PF habitually will believe in the wrong speed displayed and could get in trouble.
During my "AF447" SIM experience (I was in RHS), when the nose dipped, I suspected the V Alpha Prot issue, so I applied the OEB procedure and switched off ADR 3 and 2. The TRE then leaned forwards and put ADR 2 back on and switched off ADR 1.

But of course, he knew which ADR's he had 'failed'. I didn't.
Uplinker is offline  
Old 16th Jul 2019, 14:29
  #28 (permalink)  
 
Join Date: Nov 2004
Location: Here, there, and everywhere
Posts: 716
Originally Posted by vilas View Post

And triple ADR fail procedure doesn't say NW steering as inop.
I think that is correct. I am looking in my ,manuals and see nothing mentioned about lack of nosewheel steering.

punkalouver is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.