Change Forum... Civil Aviation Travel, Polls & Prefs Tech/Ops Aviation Hobby Aviation Photography Photography Feedback Trip Reports Military Av & Space Non-Aviation Site Related LIVE Chat My Starred Topics | Profile | New Topic | Forum Index | Help | Search
 Method Of Calculating Fuel Expenditure
 Placekicker From United States of America, joined Apr 2008, 22 posts, RR: 0Posted Sat Apr 19 2008 11:58:21 UTC (8 years 2 weeks 4 days 18 hours ago) and read 3196 times:

 Is there any roughly accurate way at determining the fuel expenditure in gallons for an aircraft based either on minutes flown or flight miles for a given aircraft? Example of what I am asking: Assume the following: 1) A flight between DTW and DFW 2) Aircraft Type: A320, B757, or Embraer 170 3) Flight Miles: 995 4) Flight Time (actual time flying): 135 minutes Are the four parameters listed above sufficient to gauge a rough estimate of how much fuel would be burned? Is there a formula given by any of the aircraft manufacturers which help estimate fuel consumption? Also, a secondary question: I assume that airlines don't fill the tanks to maximum capacity when a flight is known to only need, say 30 or 35% of a full tank. I assume the airlines save the cost of hauling the extra fuel, and would just re-fuel the needed amount at the destination. Question is, and this is purely speculative, if a flight from Detroit to Dallas is known to consume 35% of a full tank, then how much extra fuel do airlines normally allow as a buffer, for instances like circling over a storm, circiling for some miscellaneous airport delays, or unforseen extra flying which may be required? Do they allot a given percentage of fuel to buffer the occasions I just mentioned? And how much? Thanks in advance, and I appreciate any help any of you could be.
 Tb727 From United States of America, joined Jun 2005, 2051 posts, RR: 12 Reply 1, posted Sat Apr 19 2008 14:10:30 UTC (8 years 2 weeks 4 days 16 hours ago) and read 3181 times:

 I can't give you all your answers but I ran numbers for the A320 and 757 for you on this route from a flight planning perspective. I don't have the E170 profile. These numbers are from fltplan.com so I am not sure exactly how accurate they are for these 2 planes since I don't fly them, but it should give you an idea. I used the same routing for both, 894NM for the preferred routing of FWA3.FWA RBS STL RZC FSM.BYP5. A320, planned at 459 KTAS at FL360 with forecast winds for a 6pm departure: 2:20 13,908 pounds of fuel used, 2075 gal. B757, planned at 459 KTAS at FL360 with forecast winds for a 6pm departure: 2:20 18,544 pounds of fuel used, 2767 gal. I couldn't tell you the fuel prices at either airport since I don't know what the airline would pay. Generally speaking, an airplane doesn't go full fuel all the time for many reasons. A big reason is it burns fuel to carry fuel if that makes any sense. Someone that is a 121 dispatcher would have to help you with contingency fuel questions and everything else. I do all my own planning when I fly and I take a lot of things into account but I am usually doing legs at the max range of my airplane so I am usually topped off.
 Too lazy to work, too scared to steal!
 Futurecaptain From , joined Dec 1969, posts, RR: Reply 2, posted Sat Apr 19 2008 20:18:50 UTC (8 years 2 weeks 4 days 10 hours ago) and read 3156 times:

 Quoting Placekicker (Thread starter):if a flight from Detroit to Dallas is known to consume 35% of a full tank, then how much extra fuel do airlines normally allow as a buffer,

The bare minimum fuel requirement for this type of flight would be.

Fuel to fly to the destination +
Fuel to fly to the furthest alternate airport +
Fuel for any known delays enroute +
Fuel to fly for 45 minutes

 FredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26 Reply 3, posted Sat Apr 19 2008 23:20:26 UTC (8 years 2 weeks 4 days 7 hours ago) and read 3135 times:

 Aircraft manufacturers will put everything you need for fuel planning in the AFM (Airplane Flight Manual). Not just enough for a rough estimate either, it will be pretty exact. You'll have A) Taxi fuel B) Trip Fuel C) Contingency fuel, an extra 5% on the trip fuel to cover for deviations etc D) Alternate fuel, enough for an approach at the destination, climb back to altitude and the trip to the alternate E) Final reserve, 30 min holding IIRC F) Extra fuel at the discretion of the PIC to cover for shite weather, expected delays/holds and so on. Not really my area of expertise, so I'll refrain from putting more detail in. You should have enough to do a proper googling now anyway. As for your secondary question, airlines will at times haul the fuel for the next leg. Quicker turnarounds and/or fuel cost differences would probably be the main reasons. This is referred to as tankering fuel. Rgds, /Fred
 I thought I was doing good trying to avoid those airport hotels... and look at me now.
 Top Of Page Change Forum... Civil Aviation Travel, Polls & Prefs Tech/Ops Aviation Hobby Aviation Photography Photography Feedback Trip Reports Military Av & Space Non-Aviation Site Related LIVE Chat Forum Index

Reply To This Topic Method Of Calculating Fuel Expenditure
• 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.
• DETAILED RULES

 Similar topics: More similar topics...
Diff Types Of Jet Fuel posted Wed Nov 21 2001 17:33:00 by Lubcha132
What Type Of Jet Fuel Do Fighter Jets Use? posted Sun Sep 16 2001 08:57:29 by Wardialer
Basics Of The B787/A350XBW Construction Method posted Sat Jun 2 2007 08:54:22 by Superstring
Quality Controls Of Fuel..how Is This Done? posted Sun Jan 21 2007 03:38:41 by Scalebuilder
Jets Of The Eighties (Speed Or Fuel Consumption?) posted Thu Dec 21 2006 23:53:09 by Blackbird
Which A/c Burns Alot Of Fuel B747-400 Or A340-300? posted Sat Oct 28 2006 00:41:40 by AirCanada014
Mike Rowe Of Dirty Jobs Reseals A KC-135 Fuel Tank posted Thu Jul 27 2006 02:57:03 by Jetstar
Fuel Efficiency Of In-flight Refuelling Pax A/c posted Thu Jul 6 2006 08:08:11 by Art
Effect Of Temperature On Fuel Consumption & Height posted Sat Dec 24 2005 16:48:29 by Julesmusician
Fuel Flow Of Wide Bodies, Deep Analysis posted Fri Nov 4 2005 04:43:12 by Luis777
Quality Controls Of Fuel..how Is This Done? posted Sun Jan 21 2007 03:38:41 by Scalebuilder
Jets Of The Eighties (Speed Or Fuel Consumption?) posted Thu Dec 21 2006 23:53:09 by Blackbird
Which A/c Burns Alot Of Fuel B747-400 Or A340-300? posted Sat Oct 28 2006 00:41:40 by AirCanada014
Mike Rowe Of Dirty Jobs Reseals A KC-135 Fuel Tank posted Thu Jul 27 2006 02:57:03 by Jetstar
Fuel Efficiency Of In-flight Refuelling Pax A/c posted Thu Jul 6 2006 08:08:11 by Art