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

Engine A/I selection and FADEC

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

Engine A/I selection and FADEC

Thread Tools
 
Search this Thread
 
Old 10th Jul 2014, 11:43
  #1 (permalink)  
Thread Starter
 
Join Date: Nov 2002
Location: Europe
Age: 61
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
Engine A/I selection and FADEC

Hi everybody,
I used to fly with non-FADEC Engines and always I had been told to switch on/off the Engine anti ice one by one and with a delay enough to check the engine parameters to be stabilize because the change in the bleed configuration.
When I moved to A320 I could see quite a lot of colleagues switching them without any precaution and even both at the same time (using two fingers).

Is it because the FADEC is taking care of it? Is it still a good idea to do it one by one or I am getting to old?
Gryphon is offline  
Old 10th Jul 2014, 12:12
  #2 (permalink)  
 
Join Date: Mar 2002
Location: Seat 1A
Posts: 8,556
Received 73 Likes on 42 Posts
Probably differs with engine type. With my "Rollers" we switch them on one at a time. If the first one stops we know not to switch the second one on!
Capn Bloggs is offline  
Old 10th Jul 2014, 14:40
  #3 (permalink)  
 
Join Date: Jul 2013
Location: Everett, WA
Age: 68
Posts: 4,407
Received 180 Likes on 88 Posts
Many newer airplanes have auto icing detection systems that automatically turn on engine anti-ice, and it does the same thing to all engines at the same time. Hasn't been an issue.

One thing you need to watch out for with manual anti-ice - if you don't turn it on 'right away' and allow ice accumulation on the inlet, turning anti-ice on can result in a sudden large ice shed that can cause problems. For that scenario, I'd still recommend the 'one engine at a time' to make sure you're not making things worse...
tdracer is offline  
Old 10th Jul 2014, 15:33
  #4 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 4,569
Likes: 0
Received 1 Like on 1 Post
For that scenario, I'd still recommend the 'one engine at a time' to make sure you're not making things worse...
if you turned one on at a time and you got a boom and vibration, what are you going to do with the other engine ?
lomapaseo is offline  
Old 10th Jul 2014, 16:17
  #5 (permalink)  
 
Join Date: Jul 2013
Location: Everett, WA
Age: 68
Posts: 4,407
Received 180 Likes on 88 Posts
if you turned one on at a time and you got a boom and vibration, what are you going to do with the other engine ?
Obviously that would depend on the exact circumstances, but if turning on anti-ice causes an engine to surge and quit, you might want to consider seeing if you can get it restarted before moving on to the next engine...
tdracer is offline  
Old 10th Jul 2014, 19:22
  #6 (permalink)  
 
Join Date: Jan 2008
Location: farmm intersection, our ranch
Age: 57
Posts: 206
Likes: 0
Received 0 Likes on 0 Posts
FADEC or not, anytime one is making a massive change on the demand of any system it is prudent to do so with kindness to the machine.
flyingchanges is offline  
Old 11th Jul 2014, 02:15
  #7 (permalink)  
 
Join Date: Mar 2002
Location: Seat 1A
Posts: 8,556
Received 73 Likes on 42 Posts
Originally Posted by tdracer
if turning on anti-ice causes an engine to surge and quit, you might want to consider seeing if you can get it restarted before moving on to the next engine...
Ya don't say?! I doubt that Loma was asking a question...
Capn Bloggs is offline  
Old 11th Jul 2014, 08:46
  #8 (permalink)  
 
Join Date: Jan 2010
Location: USA
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
In normal flight configuration, the bleed systems are independent, so the demands on the system are no different whether you turn them off individually or simultaneously. It's really a philosophical question then. I have heard of 2-finger oopses, such as switching off both gens instead of turning on both packs...
catiamonkey is offline  
Old 11th Jul 2014, 08:50
  #9 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,404
Likes: 0
Received 0 Likes on 0 Posts
I think it has to do with new generation of engines that are not easily destabilised and very reliable relight function. First generation 747 engines used to flame out if throttled back for descent at high altitude so they had throttle restrictor bar.
vilas 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.