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

Calculated Fuel Needed - Now you need more to compensate for fuel Weight

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

Calculated Fuel Needed - Now you need more to compensate for fuel Weight

Thread Tools
 
Search this Thread
 
Old 3rd Sep 2007, 14:49
  #1 (permalink)  
Thread Starter
 
Join Date: Apr 2007
Location: Northwest
Age: 36
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Calculated Fuel Needed - Now you need more to compensate for fuel Weight

Is this Title true? Even though I have always just used a planner, I always wandered as 120,000lbs is a lot of weight in fuel so do you now not need to add extra fuel to compensate?
stevehudd is offline  
Old 3rd Sep 2007, 15:28
  #2 (permalink)  
 
Join Date: May 2000
Location: Camp X-Ray
Posts: 2,135
Likes: 0
Received 0 Likes on 0 Posts
Yes, always has been, although it should be included in your planning tables. If you want to take extra above the planned fuel then you need to factor in how much more you need just to carry that extra to destination.
Hand Solo is offline  
Old 3rd Sep 2007, 18:20
  #3 (permalink)  
Thread Starter
 
Join Date: Apr 2007
Location: Northwest
Age: 36
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Thanks for clearing that up
stevehudd is offline  
Old 3rd Sep 2007, 18:45
  #4 (permalink)  
 
Join Date: May 2000
Location: Seattle
Posts: 3,197
Likes: 0
Received 0 Likes on 0 Posts
Our computer-generated flight plans also have a fuel adjustment table for payloads up to 10 Tonnes above and below planned payload. It is expressed in Kg fuel per Tonne of payload. Beyond +/- 10T, a new flight/fuel plan has to be calculated.

I suppose you could do a double iteration to come closer to finding out how much extra fuel is burned to carry the extra fuel, but the numbers get very small very quickly.
Intruder is offline  
Old 3rd Sep 2007, 20:04
  #5 (permalink)  
 
Join Date: Feb 2005
Location: flyover country USA
Age: 82
Posts: 4,579
Likes: 0
Received 0 Likes on 0 Posts
You can always search for "Breguet Range Equation" to see the effect of the range variables.
barit1 is offline  
Old 3rd Sep 2007, 20:31
  #6 (permalink)  
Thread Starter
 
Join Date: Apr 2007
Location: Northwest
Age: 36
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Thanks guys, I am only a PPL'er but I use Level - D sim 767, Do the uk do KG instead of Lb's now. Only asking as I did flying in florida and did Lbs and the 767 i was using was in Lbs
stevehudd is offline  
Old 3rd Sep 2007, 21:25
  #7 (permalink)  
 
Join Date: May 2003
Location: france
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
fuel calculation, breguet range

hello barit 1,
"breguet range" in NM =[ L/DxTAS ]/TSFC x ln(TOW/LANDING WEIGHT)
for b738 : to account for additional fuel burn : 2.5% of the additional fuel x flight time(hrs). e.g. 3500kg extra for a 2hrs flight = 0.025x3500x2.0=175kg

kind regards,
bm

Last edited by blackmail; 3rd Sep 2007 at 21:43.
blackmail 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.