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

4 engines, one fail. Go, no go?

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

4 engines, one fail. Go, no go?

Thread Tools
 
Search this Thread
 
Old 30th Oct 2008, 01:07
  #41 (permalink)  
 
Join Date: May 2000
Location: New York
Posts: 510
Likes: 0
Received 0 Likes on 0 Posts
It depends. If you have an engine failure and you think there may be internal mechanical damage (follow the QRH), you probably want to land before you tear up the engine anymore or worse, create an imbalance that causes destructive vibration. Further, it's likely you won't have the fuel to make it to the final destination due to the drag of the inop engine and the requirement to fly lower altitudes. While you probably won't make destination, you can get the company to pick out a convenient airport where maintenance and parts are available, not to mention a good long layover hotel with a beach and pretty girls.
Roadtrip is offline  
Old 30th Oct 2008, 01:50
  #42 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 71
Posts: 3,414
Received 3 Likes on 3 Posts
Quite agree, Mr Rainboe. This has done before, but the FAA is so twin-centric; no one knows how 4-engine planes should be operated so they just apply the rules they know. (the short-sighted, know nothing idea) OR the cynical version, why let those furriners get away 4-engine ops.

The AF rule within the transport types-the bombers could depart on non-combat missions with one out, I believe.
galaxy flyer is offline  
Old 30th Oct 2008, 09:46
  #43 (permalink)  
Warning Toxic!
Disgusted of Tunbridge
 
Join Date: Jan 2005
Location: Hampshire, UK
Posts: 4,011
Likes: 0
Received 0 Likes on 0 Posts
....not if the FAA ruled military ops!

Funnily enough, I expect the B52 would be more efficient if it shut down 4 engines and operated 4 at high power? Maybe 2 shut down?
Rainboe is offline  
Old 30th Oct 2008, 14:49
  #44 (permalink)  
 
Join Date: Jul 2006
Location: USA
Posts: 451
Likes: 0
Received 0 Likes on 0 Posts
JAA vs. FAA????

What does JAA say about this...comparing to FAA 121?

It's my intrepretation of FAA 121 that the aircraft need not be landed at the nearest suitable airport in point of time IF those six criteria are satisfied. It is NOT intended that the aircraft be flown for another ten or twelve hours (over the ocean, etc.).

I am not familiar with JAA regs in this regard, so someone please educate me. I don't have any four-engine time, but I have some three-engine time.

Fly safe,

PantLoad
PantLoad is offline  
Old 30th Oct 2008, 15:01
  #45 (permalink)  
 
Join Date: Aug 2005
Location: Estonia
Posts: 834
Likes: 0
Received 0 Likes on 0 Posts
Doesn´t Nimrod have a SOP of shutting down two engines just to save fuel?

Would any civilian planes find it useful to follow suit? Starting with Comet itself...
chornedsnorkack is offline  
Old 30th Oct 2008, 15:12
  #46 (permalink)  
 
Join Date: Jan 2008
Location: Finland
Age: 77
Posts: 465
Likes: 0
Received 0 Likes on 0 Posts
We didn't shut them down but, at light weights and holding at high levels, I seem to recall the VC10 was more efficient if 2 were throttled back and 2 were at a high power setting.
finncapt is offline  
Old 30th Oct 2008, 15:12
  #47 (permalink)  
 
Join Date: Sep 2008
Location: Cedar Rapids
Age: 49
Posts: 44
Likes: 0
Received 0 Likes on 0 Posts
I believe the original post pertained to three engine ferries. At our company, they are performed by all check airman, who are all three engine qualified, and have to have done a relevant sim run in the last year (I think). Though I am not a check airman, I rode support for one regaining his three engine currency recently, and it was quite entertaining. Our numbers for a three engine dispatch are actually predicated on doing the whole takeoff on two engines, which it will do just fine, though you may need a proctologist to find the seat cushion. There is no V1 speed, or rather it is always VR, and so is dropped. Of course you want superb weather, daylight, correctly aligned stars and anything else you can think off. We actually have a couple of check airman who like doing them.
Semu is offline  
Old 30th Oct 2008, 16:36
  #48 (permalink)  
 
Join Date: Jun 2000
Location: UK
Posts: 683
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by finncapt
... I seem to recall the VC10 was more efficient if 2 were throttled back and 2 were at a high power setting.
My recollection is that the Queen of the Skies was more economical on three - i.e. with one engine actually shut down !

JD
Jumbo Driver is offline  
Old 30th Oct 2008, 19:36
  #49 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,571
Likes: 0
Received 0 Likes on 0 Posts
Would any civilian planes find it useful to follow suit? Starting with Comet itself...
This was tried many years ago
Dan Air asked the ARB (yes, that long ago, ARB) if it was permitted.
The ARB replied...NO.

End of discussion.
I believe David Davies was involved, and he shot the idea down.

With good reason, IMO.
411A 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.