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

A320 Pressing Two Buttons at Once

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

A320 Pressing Two Buttons at Once

Thread Tools
 
Search this Thread
 
Old 25th Feb 2024, 13:31
  #21 (permalink)  
 
Join Date: Aug 2005
Location: ME
Posts: 250
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by CVividasku
Nothing wrong with pushing several buttons at once in itself.
Fuel pumps for example. However, for your ears' sake, please don't put on both packs at once.
Both packs start working simultaneously if their buttons already in and you switch the bleed on. No harm to ears.
Romasik is offline  
Old 25th Feb 2024, 21:38
  #22 (permalink)  
 
Join Date: Jan 2022
Location: Miami
Posts: 93
Likes: 0
Received 0 Likes on 0 Posts
There is no FCOM limitation nor internal airline SOP that I am aware of, against pushing both batteries or both anti-ice switches at once.
321XLR is offline  
Old 25th Feb 2024, 22:57
  #23 (permalink)  
 
Join Date: Feb 2002
Location: UK
Age: 58
Posts: 3,501
Received 169 Likes on 91 Posts
Originally Posted by 321XLR
There is no FCOM limitation nor internal airline SOP that I am aware of, against pushing both batteries or both anti-ice switches at once.
It was definitely taught on our maintenance course to hit one switch at a time and wait for the response. Good airmanship etc.
TURIN is offline  
Old 25th Feb 2024, 22:59
  #24 (permalink)  
 
Join Date: Apr 2022
Location: France
Posts: 163
Received 0 Likes on 0 Posts
Originally Posted by Romasik
Both packs start working simultaneously if their buttons already in and you switch the bleed on. No harm to ears.
I'm talking about after takeoff with packs OFF.
CVividasku is offline  
Old 26th Feb 2024, 05:14
  #25 (permalink)  
 
Join Date: Feb 2018
Location: East of Westralia
Posts: 682
Received 109 Likes on 32 Posts
I’m also in the one button at a time camp.

A little like jumping in your car on a cold day and immediately setting off - nothing says not to, but a little “sympathy for the machine” can’t hurt!
ScepticalOptomist is offline  
Old 26th Feb 2024, 06:33
  #26 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,406
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 321XLR
There is no FCOM limitation nor internal airline SOP that I am aware of, against pushing both batteries or both anti-ice switches at once.
Engine anti ice switches deal with different engines and have no connection with each other. Wing anti ice has only one switch. But both batteries are part of the same system.
vilas is offline  
Old 26th Feb 2024, 06:46
  #27 (permalink)  
 
Join Date: Dec 2002
Location: UK
Posts: 2,451
Likes: 0
Received 9 Likes on 5 Posts
Long gone are the days of 'sim' start in The Lightning.
Gang bar up for 16 switches, followed by double button push for engine start.
But then that operation was designed for.

Civil aircraft may not have the design requirement, but certification testing normally identifies any suspect systems, which by convention (now requirement) are changed to protect them from errant human activity vice relying on the human 'not to do something'.
safetypee is offline  
Old 26th Feb 2024, 06:51
  #28 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,406
Likes: 0
Received 0 Likes on 0 Posts
Even pushing one has caused serious problem. In Australia one A320 or 319 when descending to 3000ft from 7000ft passing 5000ft they were cleared for approach. Pilot stabbed EXPED instead of APP then trying to press EXPED again to cancel it (that doesn't cancel EXPED) this time he stabbed ATHR causing THR LK which he disconnected using ID button which increased thrust to climb, then he disconnected AP causing 38kt flap overspeed. Pressing any switch is see, identify and do action. Any memory Muscle or otherwise or habit should play no part in it. Incidentally both PF and PNF were check pilots.
vilas is offline  
Old 26th Feb 2024, 13:19
  #29 (permalink)  
 
Join Date: Nov 2019
Location: Looking north out to sea
Posts: 50
Likes: 0
Received 9 Likes on 4 Posts
Ahh.. The five finger stab.

With most switches on Airbus or Boeing looking the same, as a trainer, I always advised to push one at a time though it may take 1 or 2 seconds longer any mistake or error could be reversed. And of course, it is a good idea to check you are at the right place, not the ones nearby. Too many times I have seen the stab effect leading to the packs coming off, fuel pumps off, anti ice on at 25C etc or in the case of one A330 I flew which had been “Boeingised” by reversing the switch direction, lights off when cleared to depart and on passing 10k in the climb.

A lesson well learnt when flying the C130 with its complex fuel system: the FE would point at the fuel source, follow to where it was needed and then push the buttons. Never saw a mistake.

Me
ItsonlyMeagain is offline  
Old 26th Feb 2024, 14:09
  #30 (permalink)  
 
Join Date: Dec 2000
Location: Lancashire
Posts: 1,251
Received 4 Likes on 3 Posts
Lear requires both batteries on at the same time. Also has identical switches with near identical names for completely opposite action. (Emer Press and Emer Depress)
blue up is offline  
Old 27th Feb 2024, 09:06
  #31 (permalink)  
 
Join Date: Aug 2007
Location: The sky
Posts: 337
Received 4 Likes on 1 Post
IMVHO the long slow poke one at a time is just good airmanship (airpersonship?) on any type.

The type of pilot that stabs quickly at buttons is also the type of pilot who doesn’t check the relevant system responds as requested. Thinking of the stages of error trapping, (Avoid, trap, mitigate), the button stabber will almost certainly be operating at the lowest level, mitigate. They’ll need ECAM / EICAS to tell them there’s a problem or will notice an issue after a period of time. The long slow poke followed by checking things are as expected (eg 1st pack on after t/o, feel the air volume entering the flight deck increase, then second pack on, same again) allows the person to operate at “trap” continuously and “avoid” if the slower actions prevent a mis selection.

The crew that is operating at the higher end of error trapping is also operating at the higher level of Situational Awareness. The levels of SA are Notice, Understand, Think Ahead (NUTA). If you correlate SA to error trapping, NOTICE = MITIGATE. UNDERSTAND = TRAP. THINK AHEAD = AVOID.

The crews who slow down and make singular selections are more likely to be operating at avoid/think ahead level which reduces their workload, avoids errors and allows them to maintain good SA, a positive feedback loop. They’re the crews most likely to have a calm, unrushed sector with a positive outcome (sim and flight).

The crews that make multiple rushed selections are more likely to make mistakes, forcing them to mitigate, upping their workload, causing them to rush, make more mistakes, mitigate again etc. a negative feedback loop. This is the crew that a sim check unravels quickly or has an incident on the line.

A calm, deliberate single selection at a time is a far more desirable behaviour than quick jabbing at buttons.

All IMVHO.

LD
Locked door is offline  
Old 27th Feb 2024, 09:53
  #32 (permalink)  
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,295
Received 139 Likes on 63 Posts
And on the 'bus - read the panel section on the side and then move across to the button needing the action .

"Fuel"
"Crossfeed"
"On"



@lockeddoor - it's "airperchildship" as "son" is gendered . Though some say that "child" is ageist, I haven't gone that far yet.
/s
compressor stall is online now  
Old 27th Feb 2024, 14:02
  #33 (permalink)  
 
Join Date: Feb 2003
Location: Blue sky
Posts: 276
Received 7 Likes on 6 Posts
Originally Posted by safetypee
Long gone are the days of 'sim' start in The Lightning.
Gang bar up for 16 switches, followed by double button push for engine start.
But then that operation was designed for.

Civil aircraft may not have the design requirement, but certification testing normally identifies any suspect systems, which by convention (now requirement) are changed to protect them from errant human activity vice relying on the human 'not to do something'.
Technically there is probably nothing wrong with pushing or not pushing those buttons at the same time. Humanly there is a lot to discuss... it’s the basis of why your lightning had a gang bar to start (military ops, 16 manipulations vs 1 under strong time pressure), and ie the 737 only to activate lights. Years ago there was a tv show on a certain Air Force with a pilot explaining his nickname: TOBI. Turn On Battery Idiot. Had to swap aircraft on quick react because it refused to start.

As we are not out on intercepts, let’s train them to go consciously step by step so they don’t get lost when systems don’t react as we expect them to? Let’s walk.

Last edited by BraceBrace; 28th Feb 2024 at 14:22.
BraceBrace is offline  
Old 27th Feb 2024, 16:15
  #34 (permalink)  
 
Join Date: Aug 2005
Location: ME
Posts: 250
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by CVividasku
I'm talking about after takeoff with packs OFF.
Ah... Makes sense then. Never did it in my life (Packs off take off that is), so this didn't come to my mind 🙃
Romasik is offline  
Old 27th Feb 2024, 16:36
  #35 (permalink)  
 
Join Date: Nov 2016
Location: FLSomething
Posts: 404
Received 0 Likes on 0 Posts
Originally Posted by TURIN
It was definitely taught on our maintenance course to hit one switch at a time and wait for the response. Good airmanship etc.
But that was that just an instructor’s ‘ism’ that they themself picked up from being an engineer on the Herc in the ‘60s?
VariablePitchP is offline  
Old 28th Feb 2024, 08:48
  #36 (permalink)  
 
Join Date: Sep 2011
Location: FL390
Posts: 238
Likes: 0
Received 0 Likes on 0 Posts
There are no technical issues with two switches at once - they're either hardwired to their respective system or the switch positions of the whole panel are polled and sent out over a data bus.

It is, in my opinion, unprofessional. Much like some crews who seem to pride themselves on running through ECAM as quickly as possible instead of sitting on their hands for a bit, pushing the button and making sure it does what you expected is just common sense. Fuel pump / battery / anti-ice / pack... it doesn't matter. Taking just a second or two to think through what you're about to do instead of relying on instinct is the way forward.

As a very new co-pilot on A320, I was a little too enthusiastic in my first non-normal in the FFS. "GEN 1... OFF THEN ON". Reached up and jabbed the button. A lot of relays and contactors clunking, followed by a silence broken only by the trainer wetting himself with laughter taught me a valuable lesson.
Fursty Ferret is offline  
Old 28th Feb 2024, 12:26
  #37 (permalink)  
 
Join Date: Mar 2002
Location: near an airplane
Posts: 2,794
Received 52 Likes on 42 Posts
Originally Posted by skycomparison
Hey there! So about pressing two buttons at once on the A320, it's actually not a big deal for some controls like batteries or packs/bleeds.
You can use the BAT switches for an interesting lesson in itself. My students would hit one, then observe that one switch was dark while the other had a message lit up. This of course led them to think that they needed to then push the dark switch, which switched that particular battery OFF again. It would lead to a quick recap of the dark cockpit concept (and the 'read the instructions' bit... the lit up message clearly states 'OFF').

We use a touchscreen based procedure trainer that only accepts one input at a time anyway at the touchscreens are not multi-touch
Jhieminga is offline  
Old 28th Feb 2024, 13:11
  #38 (permalink)  
 
Join Date: Dec 2001
Location: GA, USA
Posts: 3,211
Likes: 0
Received 23 Likes on 10 Posts
Modern systems are certainly not flawless and the old adage of ‘undo what you did last’ certainly still applies.
You can generate all sorts of transient gremlins in an electrical system when mashing buttons.
In pneumatic, fuel and hydraulic systems you can have valves that move slow or are briefly stuck while flow starts or pressure builds.
Theres no purpose in trying to turn everything on in 0.3 seconds.
B2N2 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



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.