blueone

I am very interested in how much fuel I consume a particular flight. If one knows the distance traveled, type of aircraft, number of passengers+cargo, how can one calculate average fuel burn for any particular aircraft?

Any good references?

skylane

Fuel burn is expressed in quantity of fuel (either lbs or gallons) burned per hour (not per distance since winds are a factor). You can get the fuel burn rate from the POH (Pilot Operating Handbook) for the aircraft in question.

So, to figure out the amount of fuel burned during a trip...
1. Map out the distance
2. Determine the winds aloft
3. Determine the ground speed (air speed compensated for winds aloft)
4. Determine the time in the air given the distance and the ground speed
5. Given the time in the air - multiple by the fuel burn rate to get total fuel consumed

The fuel used during climbs and descents are available in the POH (Pilot Operating Handbook) for the aircraft in question. These charts give you the amount of fuel used, time to reach the altitude and the distance traveled during the climb.

ClimbGuy

please tell me your not trying to be one of those carbon neutral people. When calculating your fuel do you want to know how much your seat uses? How do you want to account for empty seats/cargo? If you get upgraded do you count the J/F fuel burn or the Y burn?

blueone

Don't need to stink up an attitude on a totally neutral question.

Bobster

I found some actual data extracted from airline company reports.

JetBlue, Airbus 320, 1358 mile average stage length, 0.447 mpg (gasoline equivalent), or 67.9 passenger mpg full flight, 58.1 pmpg typical flight.

Southwest Airlines, Boeing 737 "next generation", 607 mile average stage length, 0.430 mpg, or 58.9 passenger mpg full flight, 41.7 pmpg typical flight.

Source for the above data: http://strickland.ca/efficiency.html

The average now for all airlines is about 47 passenger mpg which is a big improvement over what it was in 2000, and a really huge impovement over the past few decades.

It's interesting to note that a 747 travels less than 800 feet on a gallon of gas. When you look at it that way, it sounds really awful.

MisterNice

I predict the OP soon may be getting a visit from the TSA or the FBI.

MisterNice

OttoMH

In the UK/Europe we're actually encouraged to ask this sort of question ^

Efrem

There are two separate questions here. Knowing how much the aircraft consumes doesn't tell you how much of that you're responsible for. If it consumes X tons to carry 100 pax, it doesn't follow that if you weren't on the plane it would use 1 percent less. The saving would be far smaller than that, since one more passenger doesn't increase the weight of the airframe, etc. As long as it's going to fly anyhow, which it usually must even if there are no passengers because it's needed at its destination for its next flight, it's going to burn most of that fuel independently of passenger load. The incremental consumption resulting from another 200 lbs,/90 kg to carry, or whatever you, your clothes and your baggage weigh, is tiny.

Bobster

My car weighs 4000 pounds. I weigh 180. So if I my trip requires 10 gallons of gas, I am actually only consuming 0.43 gallons. Cool.

altaskier

They would not be flying the planes if there were no passengers (cargo excepted). They would not be flying a 747 if the average passenger load were 300, or a 777 if the load were 200, or ...

And they would not fly the route at all if there weren't customers who "asked" them to.

Therefore while the marginal fuel use from adding one more passenger might be really tiny, the only rational way to count the fuel use is total per plane divided by passengers per plane. The airlines set up their schedules based on how many people want to fly from A to B at such-and-such time (at least on average), so in a sense they've included you as one of their justifications for flying the route.

st7860

he might be one of those al gore types.

Efrem

That would fall under the "as long as it's going to fly anyhow" caveat, in the part you didn't quote of the post you quoted in part. If your car could and would make the same trip without you, you're right!

N965VJ

There’s bound to be some Carbon Offset calculators on the internet – if that’s what you’re in to.

Bobster

My car has been towed several times. Towing a car is conceptually no different from flying an empty airplane on a ferry flight. That's why I didn't quote that part of your post. It was irrelevant.

SmilingBoy

Don't think so. There are many better ways. I think a good way would be to take the total consumption of the plane, and then apportion it according to ticket price. Ticket price will correspond quite closely to how much more likely you make it that a plane flies.

In the end, the question is moot. Carbon-offsetting doesn't make sense in the way it is being applied now. What would more make sense is to put a price on each gallon of jet fuel burnt. The airlines will then take this into account and change their behaviour accordingly. (Note: I don't advocate this, but suggest that this would be a more sensible method than the carbon offsetting currently in fashion. Most notably, one should not only target air traffic, which is only a small source of CO2, but all sources of CO2. It would be much cheaper and more efficient to reduce CO2 reduction by improving the insulation of houses.)

SmilingBoy.