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

What is the reason for turning off fuel pumps after shutdown.(a320)

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

What is the reason for turning off fuel pumps after shutdown.(a320)

Old 10th Jun 2020, 16:15
  #21 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,680
Yes? And once the cockpit preparation is finished the fueller is still hooked up. Look, sometimes they've finished but sometimes they haven't, there is nothing in our SOPs that ensures the fuelling has finished before the PF does the overhead panel.​​​​​​
Going strictly by literature, it says during cockpit preparation no white light. So either put the fuel pumps on during refuelling or do the prep after refuelling. I am sure you are aware of the A320 incident where the crew taxied, took off and climbed to 370 when both engines flamed out and during dual engine flame out procedure they realized that the fuel pumps were off. They relit engines came back and landed.
vilas is online now  
Old 10th Jun 2020, 18:21
  #22 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by Denti View Post
Really?

With a 25 minute turnaround, the fueller connects as soon as the doors are opened, and the flightdeck crew will start with the cockpit preparation as soon as they have finished the post-flight flows.
How do you accomplish a 25 minute turn in an A320? The shortest Iíve seen is closer to 45 mins maybe.
Check Airman is offline  
Old 10th Jun 2020, 19:41
  #23 (permalink)  
Cak
 
Join Date: Feb 2010
Location: At home
Age: 38
Posts: 95
It is possible to do it even faster
Some low costers have 25-30 min as standard turnaround time
Cak is offline  
Old 10th Jun 2020, 19:43
  #24 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting home
Age: 42
Posts: 3,009
Originally Posted by Check Airman View Post
How do you accomplish a 25 minute turn in an A320? The shortest I’ve seen is closer to 45 mins maybe.
35 is the target for quite a large portion of the European ops. Doable, for anything below 30 in my personal experience the crew procedures become limiting.

Otherwise, the critical path is the cabin. Hence:
- remote parking, 2 sets of stairs
- deplane 5 minutes
- 10 min cleaning
- 5 min CC procedures, security check
- 10 min pax boarding
- 2 min head-count
- 3 minutes for engine start (IAE)

It is necessary for CC to be exactly on their marks for the above, needless to say it is the redcap who runs the show. The weakest link in my experience is the delay between cleaners leaving and first PAP stepping inside.

Last edited by FlightDetent; 10th Jun 2020 at 22:48.
FlightDetent is offline  
Old 11th Jun 2020, 02:02
  #25 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by FlightDetent View Post
35 is the target for quite a large portion of the European ops. Doable, for anything below 30 in my personal experience the crew procedures become limiting.

Otherwise, the critical path is the cabin. Hence:
- remote parking, 2 sets of stairs
- deplane 5 minutes
- 10 min cleaning
- 5 min CC procedures, security check
- 10 min pax boarding
- 2 min head-count
- 3 minutes for engine start (IAE)

It is necessary for CC to be exactly on their marks for the above, needless to say it is the redcap who runs the show. The weakest link in my experience is the delay between cleaners leaving and first PAP stepping inside.
Impressive. Most of our outstations are planned for about a 1 hr turnaround. Rare to see under 50 minutes. If your day includes going through one of the hubs, 1.5 - 3 hrs is typical.
Check Airman is offline  
Old 11th Jun 2020, 02:20
  #26 (permalink)  
 
Join Date: Jan 2004
Location: Here and there
Posts: 2,851
Originally Posted by vilas View Post
Going strictly by literature, it says during cockpit preparation no white light. So either put the fuel pumps on during refuelling or do the prep after refuelling. I am sure you are aware of the A320 incident where the crew taxied, took off and climbed to 370 when both engines flamed out and during dual engine flame out procedure they realized that the fuel pumps were off. They relit engines came back and landed.
That's what we do. We just do the cockpit prep, including fuel pumps, while the fuel is going on. All I'm saying is that if it is important that fuel pumps are left off until fuelling is complete then it is poorly communicated. Assuming that cockpit prep is done after fuelling is completed doesn't cut it.
AerocatS2A is offline  
Old 11th Jun 2020, 14:27
  #27 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,680
Originally Posted by Check Airman View Post
Impressive. Most of our outstations are planned for about a 1 hr turnaround. Rare to see under 50 minutes. If your day includes going through one of the hubs, 1.5 - 3 hrs is typical.
Many Asian LCCs turn around in 25mts.
vilas is online now  
Old 11th Jun 2020, 19:36
  #28 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,126
In a previous company where we still had aircraft cleaning we planned 45 minutes for an A321, and that was very much manageable. In a LCC world where there is no aircraft cleaning during turn around, just a short tidy by the cabin crew which includes the security check. Head count is not necessary, and thankfully engine start is a bit faster on the CFM, except the LEAP if you are unlucky enough to have a NEO.
Denti is offline  
Old 11th Jun 2020, 22:48
  #29 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by vilas View Post
Many Asian LCCs turn around in 25mts.
Gosh. I don't think I've ever done a 25 minute turn. Even when flying a regional jet.
Check Airman is offline  
Old 11th Jun 2020, 22:51
  #30 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by Denti View Post
In a previous company where we still had aircraft cleaning we planned 45 minutes for an A321, and that was very much manageable. In a LCC world where there is no aircraft cleaning during turn around, just a short tidy by the cabin crew which includes the security check. Head count is not necessary, and thankfully engine start is a bit faster on the CFM, except the LEAP if you are unlucky enough to have a NEO.
Interesting that a few replies here have mentioned engine start as part of the turnaround time. Why's that? Here, most companies measure the turn time from IN to OUT on the ACARS, so it'd be a few minutes between OUT and engine start.
Check Airman is offline  
Old 11th Jun 2020, 23:45
  #31 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting home
Age: 42
Posts: 3,009
No jetty for the superquick ops. AOBT is the first movement.

In reality a flash turnaround can be achieved, even repeatedly. But maybe 30%? There would be a padding in the block-flight-block times, to allow some schedule recovery. With a PRM passenger everything goes to hell. Unless you are flying for one of the three strongest LoCos, where penalties on the ground service providers are dire. And everyone else needs to wait.

What was this thread about again? Oh that, shared 2 years ago
Originally Posted by MAR18
I read the explanation with a bit of sadness.

[...] went to great lengths to wipe off the habit of leaving the pumps OFF, citing the no-white-lights rule. Now, 7 years later on the internet, I read that it does not apply to Fuel Pumps before refuelling ends? Yuck. And maybe that the AMM even specifies so!

Their logic that SOPs are well applied because during CKPT PREP the re-fuelling is finished is utter rubbish. That was NEVER true at any turn-around, since A320 day 1.
FlightDetent is offline  
Old 12th Jun 2020, 03:03
  #32 (permalink)  
 
Join Date: Jan 2004
Location: Here and there
Posts: 2,851
Originally Posted by Check Airman View Post
Interesting that a few replies here have mentioned engine start as part of the turnaround time. Why's that? Here, most companies measure the turn time from IN to OUT on the ACARS, so it'd be a few minutes between OUT and engine start.
Yeah, a push back is an extra 5 minutes leeway on the turn time.
AerocatS2A is offline  
Old 12th Jun 2020, 05:10
  #33 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by AerocatS2A View Post
Yeah, a push back is an extra 5 minutes leeway on the turn time.
Iím not really understanding this. I know that a lot of European airports use remote stands. Is this really factored into the turn times?
Check Airman is offline  
Old 12th Jun 2020, 05:12
  #34 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Originally Posted by FlightDetent View Post
No jetty for the superquick ops. AOBT is the first movement.

In reality a flash turnaround can be achieved, even repeatedly. But maybe 30%? There would be a padding in the block-flight-block times, to allow some schedule recovery. With a PRM passenger everything goes to hell. Unless you are flying for one of the three strongest LoCos, where penalties on the ground service providers are dire. And everyone else needs to wait.

What was this thread about again? Oh that, shared 2 years ago
Iíve only deplaned via stairs a few times, but the turn time was always the same. If anything, the rear door is only usually opened for the cleaners to board.
Check Airman is offline  
Old 12th Jun 2020, 06:14
  #35 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,126
Originally Posted by Check Airman View Post
Iím not really understanding this. I know that a lot of European airports use remote stands. Is this really factored into the turn times?
Well, yes and no. On a push back stand engine start up time doesn't factor as the engine is started during push back, after off block. However, on a taxi-out stand it does factor as the engine is started on stand and off block happens after that. Some airlines use a special "self maneuvering" delay code to track that.

Iíve only deplaned via stairs a few times, but the turn time was always the same. If anything, the rear door is only usually opened for the cleaners to board.


Even in a legacy carrier before i joined some LCCs we were happy to park on a remote stand, boarding and deboarding via two stairs is simply much faster than with just one entry. And yes, if possible, we always let the passengers deplane via both exits, it is nice for them and better for us.
Denti is offline  
Old 12th Jun 2020, 07:06
  #36 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,840
Thanks for the clarification on the delay code. Never seen that tracked here. I quite like the stairs, if Iím being honest. Shame we donít do it more- as long as the weatherís cooperating.
Check Airman is offline  
Old 12th Jun 2020, 07:40
  #37 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting home
Age: 42
Posts: 3,009
Point being for below 30 min you pretty much need two stairs so there are no dual turnaround targets, rather the airline might selectively choose to use remote only. Also, failure of turning on time has financial implications for the GHA. Having a SLA that specifies turnaround extra of 5 mins = 300 EUR penalty is not unheard of. Then it's fair to allow 3 minutes for engine start, once things are getting Excel'd. If the Teutonic system come up with a dedicated delay code, nobody really is surprised.
FlightDetent is offline  
Old 12th Jun 2020, 07:43
  #38 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting home
Age: 42
Posts: 3,009
Originally Posted by Check Airman View Post
I quite like the stairs, if I’m being honest. Shame we don’t do it more- as long as the weather’s cooperating.
Careful what you wish for. Imagine the cockpit load, more especially the lack of any lull to rev the brain down, if the target turnaround becomes 35 min. The GHA will learn how to match that so, day in and out, you'll be expected to make it too. Not to mention the possibility of 5 sector days.
FlightDetent is offline  
Old 12th Jun 2020, 08:19
  #39 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,126
Originally Posted by FlightDetent View Post
Careful what you wish for. Imagine the cockpit load, more especially the lack of any lull to rev the brain down, if the target turnaround becomes 35 min. The GHA will learn how to match that so, day in and out, you'll be expected to make it too. Not to mention the possibility of 5 sector days.
Indeed, doing only minimum turnarounds can be very fatiguing. Especially for the PM (who does the walkaround where i work, but also the load calculation) it can be hard to get enough breathing time to visit the loo, especially when he is new to the operation.

So even if the working conditions are good, which they are at some outfits, although that might change now very fast, LCC flying is very hard work indeed, for both cabin crew and flight deck.
Denti is offline  
Old 12th Jun 2020, 10:17
  #40 (permalink)  
 
Join Date: Jan 2004
Location: Here and there
Posts: 2,851
Originally Posted by Check Airman View Post
Iím not really understanding this. I know that a lot of European airports use remote stands. Is this really factored into the turn times?
It doesn't need to be factored in, but if you have a 35 minute turn around every time but some are push-backs and some are taxi-out, you effectively have an extra 4 - 5 minutes on the push back turn compared to the taxi-out turn. Where I currently work, every turn is a push back so it's a moot point, but I used to do freight with 35 minute turns and the little bit of extra time you got at the push-back ports made all the difference.

Originally Posted by Denti
Indeed, doing only minimum turnarounds can be very fatiguing. Especially for the PM (who does the walkaround where i work, but also the load calculation) it can be hard to get enough breathing time to visit the loo, especially when he is new to the operation.

So even if the working conditions are good, which they are at some outfits, although that might change now very fast, LCC flying is very hard work indeed, for both cabin crew and flight deck.

To each, their own. Personally I'd much rather do a four sector day with minimum turn times rather than have a five to ten minute lull each time. Get to work, bang out the sectors, go home, that's my ideal work schedule.
AerocatS2A is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

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