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

A320 AoA Display

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

A320 AoA Display

Old 27th Apr 2019, 13:28
  #1 (permalink)  
Thread Starter
 
Join Date: Apr 2007
Location: earth
Posts: 78
Likes: 0
Received 0 Likes on 0 Posts
A320 AoA Display

Hi,

Reading an ATSB report on an A320 with unreliable airspeed near Perth, Western Australia AO-2015-107.

[/QUOTE] In the A320, flight crew are able to examine the ADR angle-off attack values; however, they are not presented on the primary flight displays, and require the flight crew to access and display a page on the multipurpose control and display unit in the centre pedestal. In this occurrence, the flight crew discussed an angle of attack discrepancy, but for undetermined reasons did not access the angle of attack page to confirm the discrepancy. [QUOTE]

How common is it to check the AoA in flight to troubleshoot an ECAM of NAV ADR DISAGREE ?

How do you access this info ? FCOM have any guidance ?






novice110 is offline  
Old 27th Apr 2019, 13:45
  #2 (permalink)  
 
Join Date: Mar 1999
Location: big green wheely bin
Posts: 887
Likes: 0
Received 0 Likes on 0 Posts
MCDU MENU/AIDS/ALPHA DISPLAY/AOA. It will then give you the respective AOA for each ADC.

Its not an approved procedure, so I’m surprised that the ATSB have come to that conclusion.

We used to have a list of all the ALPHA codes that you could display in the MCDU, but it’s long since been lost.
Jonty is offline  
Old 27th Apr 2019, 13:45
  #3 (permalink)  
 
Join Date: Jun 2018
Location: Vladivostok
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
MCDU MENU-AIDS-ALPHA CALL UPS - AOA
Sergei.a320 is offline  
Old 27th Apr 2019, 14:19
  #4 (permalink)  
 
Join Date: Feb 2017
Location: Isla Grande
Posts: 996
Received 0 Likes on 0 Posts
alpha codes
gearlever is offline  
Old 27th Apr 2019, 15:11
  #5 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,402
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by novice110
Hi,



How common is it to check the AoA in flight to troubleshoot an ECAM of NAV ADR DISAGREE ?
Not common as it is not a procedure nor the purpose of the AIDS function which is to monitor and record many different parameters so that they can be analysed when appropriate. It is common during line training of new type rated pilots to call up a few pages just to show the trainees the capabilities of the system and possibly induce some technical & aerodynamics chats but that's it. Definitely nothing to mess with during abnormal procedures.
sonicbum is offline  
Old 27th Apr 2019, 17:42
  #6 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,302
Received 3 Likes on 3 Posts
The suggestion of an Investigation Board that crew should have probed some raw data bus via what is essentially a maintenance system, while airborne during an abnormal which affected the primary flight instruments, is bizarre.

Last edited by FlightDetent; 28th Apr 2019 at 05:00. Reason: Grammar
FlightDetent is offline  
Old 27th Apr 2019, 18:00
  #7 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,396
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by FlightDetent
The suggestion of an Investigation Board, that crew should have probed some raw data bus via what is essentially a maintenance system, in flight and during an abnormal that affected primary flight instruments, is bizarre.
Surely! I doubt any commercial aircraft has AoA displayed on the instrument panel. I think the investigation board was not briefed properly on the Nav ADR disagree procedure and function of the MCDU AoA recorded value. I hope next time they don't suggest some non standard CB reset. That will be a disaster.
vilas is offline  
Old 27th Apr 2019, 18:48
  #8 (permalink)  
 
Join Date: Jul 2007
Location: World
Posts: 2,551
Likes: 0
Received 0 Likes on 0 Posts
In my company we cannot access those pages as per our SOPs, unless instructed by engineers on the phone.
dirk85 is offline  
Old 27th Apr 2019, 19:24
  #9 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,497
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by vilas
Surely! I doubt any commercial aircraft has AoA displayed on the instrument panel.
First of all, it was displayed on A320s in the low 100 MSNs, so there is actually an example of the type in question, although not on the primary displays, but rather as an additional instrument. And of course, the 737NG offered an AOA display for 15 years or so on the PFD as a customer option. Of course driven by the request of the military customers but also used by airlines including American Airlines. Not to mention, most, if not all civilian HUD installations display AOA as well.
Denti is offline  
Old 27th Apr 2019, 21:07
  #10 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,402
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Denti
First of all, it was displayed on A320s in the low 100 MSNs, so there is actually an example of the type in question, although not on the primary displays, but rather as an additional instrument.
AFAIK/remember on the A320 it used to be (prior to the BUSS) an option as well.
sonicbum is offline  
Old 27th Apr 2019, 21:47
  #11 (permalink)  
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,282
Received 130 Likes on 59 Posts
Aircraft is MSN 429.
compressor stall is offline  
Old 28th Apr 2019, 00:16
  #12 (permalink)  
Thread Starter
 
Join Date: Apr 2007
Location: earth
Posts: 78
Likes: 0
Received 0 Likes on 0 Posts
Thanks for the info all.

The report goes into much detail, worth a read for beginners like me. I believe it infers the crew should have accessed this maintenance function, without training or procedures to follow. Can you imagine the results if crews started using such unapproved functions, at the expense of ECAM and A-N-C, in a time critical unreliable airspeed situation ?
novice110 is offline  
Old 28th Apr 2019, 08:15
  #13 (permalink)  
 
Join Date: Jul 2010
Location: Asia
Posts: 1,529
Received 45 Likes on 27 Posts
The Back Up Speed System is a huge improvement, just keep the needle in the green.
krismiler is offline  
Old 28th Apr 2019, 18:08
  #14 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 2,509
Likes: 0
Received 0 Likes on 0 Posts
I don't think that anyone could reasonably expect a crew facing difficulty controlling a plane with unreliable airspeed to go digging to find AoA.

I agree with the above posters that it should be permanently displayed on the PFD.
Check Airman is offline  
Old 28th Apr 2019, 20:19
  #15 (permalink)  
 
Join Date: Oct 2013
Location: Wengen
Age: 53
Posts: 380
Likes: 0
Received 0 Likes on 0 Posts
AOA indicator as well HUD was standard on IT (Air Inter) A320 however GPWS was surprisingly NOT!

Vous savez que le BEA a recommandé dans son rapport sur le Rio-Paris « l’installation d’un indicateur d’incidence sur tous les avions de ligne »
Réaction des constructeurs : NADA !
Winnerhofer is offline  
Old 29th Apr 2019, 07:51
  #16 (permalink)  
 
Join Date: Sep 2011
Location: FL390
Posts: 226
Likes: 0
Received 0 Likes on 0 Posts
AoA is there if you want to use it, via HUD if fitted or on the PFD if you use TK/FPA.
Do you mean the bird/FPV? If everything is working it gives you an *approximation* of your AoA, but unless you know the angle of incidence it'll only ever be that: an approximation. Given that the FPV uses a combination of air data and inertial sources, I'd caution very strongly against referencing it for anything where you might have an unreliable air data situation. Even if you have the numerical value, it's not helpful unless you have a benchmark. I wouldn't go searching around for a small number in the corner of the PFD when the difference between stall and un-stalled is 1 degree or less at high levels.

What you could do is have a system that looks at the current AoA, and the stall AoA, and have a synthetic voice call out "STALL" if one exceeds the othe- oh, wait.

If you're in any doubt about the situation, and it's shouting "stall", then do the stall recovery procedure. Otherwise set pitch and power memory items and WAIT until the situation stabilises.
Fursty Ferret is offline  
Old 29th Apr 2019, 10:52
  #17 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,396
Likes: 0
Received 0 Likes on 0 Posts
Not a fan of the BUSS, find it too sensitive, far prefer to set an attitude and power.
With all three ADRs off the Flt Ctls are in alternate law. There is no reason for the aircraft to be any more sensitive than it is supposed to be. Now in A350 Airbus has come out with alternate speed calculation and backup speed. They have quadruple ADR redundancy( B737MAX has zero) and alternate speed calculation using AOA, load factor and weight which is fed into the lift equation to get back up speed which is compared with ADR speed. If there's a discrepancy between ADR speed the system will generate a warning and automatically change to back up speed. In future A 320 and A330 will have option of this. So with UAS all that apilot does is say thank you and ask for a coffee.
vilas is offline  
Old 29th Apr 2019, 14:35
  #18 (permalink)  
 
Join Date: Mar 1999
Location: big green wheely bin
Posts: 887
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by vilas
With all three ADRs off the Flt Ctls are in alternate law. There is no reason for the aircraft to be any more sensitive than it is supposed to be. Now in A350 Airbus has come out with alternate speed calculation and backup speed. They have quadruple ADR redundancy( B737MAX has zero) and alternate speed calculation using AOA, load factor and weight which is fed into the lift equation to get back up speed which is compared with ADR speed. If there's a discrepancy between ADR speed the system will generate a warning and automatically change to back up speed. In future A 320 and A330 will have option of this. So with UAS all that apilot does is say thank you and ask for a coffee.

Now that I like!
Jonty is offline  
Old 29th Apr 2019, 15:12
  #19 (permalink)  
 
Join Date: Feb 2017
Location: Isla Grande
Posts: 996
Received 0 Likes on 0 Posts
Originally Posted by vilas
With all three ADRs off the Flt Ctls are in alternate law. There is no reason for the aircraft to be any more sensitive than it is supposed to be. Now in A350 Airbus has come out with alternate speed calculation and backup speed. They have quadruple ADR redundancy( B737MAX has zero) and alternate speed calculation using AOA, load factor and weight which is fed into the lift equation to get back up speed which is compared with ADR speed. If there's a discrepancy between ADR speed the system will generate a warning and automatically change to back up speed. In future A 320 and A330 will have option of this. So with UAS all that apilot does is say thank you and ask for a coffee.
Love your last sentence

Last edited by gearlever; 29th Apr 2019 at 15:44.
gearlever is offline  
Old 29th Apr 2019, 16:49
  #20 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,402
Likes: 0
Received 0 Likes on 0 Posts
By the way I hope there will still be airlines where You don't have to pay for that coffee (ok I shut up) ;-)
sonicbum 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 © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.