Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Fadec Limit?  
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Posted (12 years 11 months 1 week 23 hours ago) and read 1223 times:


Can a pilot using a plane with FADEC firewall the engines, or overboost them in any way? Or is it like Fly-By-Wire, where it restrains any excessive setting?

Or is it like Airbus and Boeing where it depends on company?

-BB78

4 replies: All unread, jump to last
 
User currently offlineMusang From United Kingdom, joined Apr 2001, 845 posts, RR: 7
Reply 1, posted (12 years 11 months 1 week 17 hours ago) and read 1161 times:

On the Avro RJ 100 the fadec limits the engines to 97% N1, 98.8% N2 and EGT of 613 degrees max continuous, 632 on take off and 649 in windshear escape mode. So you could firewall the engines although there would be no point except in dire emergency.

The Thrust Control Sytem (TRP + FADEC) sets the N1 reference value based on atmos. conditions for the air bleed config. selected, we use Reduced thrust most of the time and Max when operationally necessary, but this will still be 3 or 4 % short of the FADEC limit N1. FADEC also limits the engines minimum speeds; the N2 Floor changes according to ambient conditions and the bleeds selected.

Regards - Musang


User currently offlineBuzz From United States of America, joined Nov 1999, 697 posts, RR: 22
Reply 2, posted (12 years 11 months 1 week 14 hours ago) and read 1149 times:

Hi Balckbird, Buzz here. Well it's possible to overboost a 757 (PW2000) or A320 (V2500) engine.... but it has to have a couple types of EEC-FADEC failure first. And people are trained not to ram the throttles (pardon me, i play with taildraggers) back and forth with abandon, so ifyou have a dying engine, it might happen, but sure is unlikely. I haven't heard of it in the lst several years at UAL.
g'day


User currently offlineGt1 From United States of America, joined Feb 2001, 133 posts, RR: 0
Reply 3, posted (12 years 11 months 2 days 9 hours ago) and read 1129 times:

On the PW4000 (94") and CF6-80C2 FACEC engines, the EEC will limit the engine in the "Normal mode" for 3 parameters: N1 & N2 overspeed, and "Overboost", which is PS3 pressure. PS3 is "pressure, static, station #3", which is to say the outlet of the high pressure compressor, or if you prefer, the inlet to the combustion chamber. If memory servers, the actual pressure is in the 475-500 psi range for both engines.

In the "Alternate mode", which is "N1" for PW, and "Reversionary" for the CF6, overboost protection is lost, leaving you with only N1 & N2 overspeed protection.

Note that neither engine protects for EGT.

One last thing, I would suggest that you could say a FADEC system IS a fly-by-wire system. There are no cables between the throttles and the fuel metering component.


User currently offlineA/c train From United Kingdom, joined Jun 2001, 501 posts, RR: 4
Reply 4, posted (12 years 11 months 1 day 5 hours ago) and read 1101 times:

Were about's in East Sussex are you from Musang?

Top Of Page
Forum Index

Reply To This Topic Fadec Limit?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
CRJ Fadec posted Thu Apr 20 2006 05:58:53 by AirWillie6475
Any Aircraft Equipped With FADEC? posted Tue Apr 11 2006 04:36:03 by Spikebe90
What Is Volume Limit posted Sat Apr 1 2006 22:04:03 by AirA380
757 Altitude Limit With Downed Computer posted Sun Mar 19 2006 17:45:14 by Runallnight
What Purpose Serves The 250k Speed Limit? posted Sat Jan 21 2006 01:59:32 by TheSonntag
757 EPR Limit posted Tue Aug 2 2005 01:20:02 by Taguilo
"Speed Limit 270kias/M0.82" They're Very Different posted Sun Jul 10 2005 08:07:17 by Bio15
Landing On Very Short Runway: Limit For 737? posted Wed Jun 22 2005 12:37:23 by Klm-md11
Climb Limit, BFL, Performance Limited Questions.. posted Sun Feb 6 2005 21:09:01 by Pilotaydin
Airbus Cockpit Tray Weight Limit posted Fri Dec 24 2004 04:55:58 by Goboeing

Sponsor Message:
Printer friendly format