On jets

I’ve been active on the online sailing communities looking for a ride from *anywhere* on the west coast of the North American continent to Hawaii. I’m preparing my pitch to the container ship companies for Monday. I also decided to take a closer look at the numbers on jet travel. Here’s some figures snatched at random from the WWW.

B747-400 fuel burn LHR-JFK 65,000 Kgs / 17,800 gallons

The flight from London Heathrow Airport to New York John Fitzgerald Kennedy Airport is 3452 miles. That puts the 747 at around 5 mpg, which is also posted on Boeing’s 747 ‘fun facts’ page.

Boeing 747

  • mpg = 5
  • passengers = 400-450
  • cost = US$228-260 million (2007)

Boeing 747 LHR-JFK flight

  • 17,800 gallons / 400 passengers = 44 gals/passenger.
  • 3,452 miles / 44 gallons = 78 mpg (per passenger)
  • $400/ticket (purchased in advance) x 400 tickets = $160,000/gross profit per flight
  • Total cost of 747 ($228,000,000) / gross profit per flight ($160,000) = 1,425 flights
  • Since my gross profit doesn’t include any costs (eg fuel, salaries, insurance, maintenance, financing etc.) the number of flights between LHR and JFK needed to break even is much higher. Let’s say 2,500 flights just for fun.
  • 2,500 x 17,800 gallons = 44,500,000 gallons of fuel that must be burned to break even on the cost of the plane.

According to www.fueleconomy.gov burning a gallon of gasoline produces 20 lbs of carbon. It’s likely different for jet fuel, but anyway…

17,800 gallons x 20 lbs = 356,000 lbs of carbon / 400 people  = 890 pounds of carbon per person for a flight from LHR to JFK.

That’s 5 times my body weight in carbon. So what? I’ll plant 40 saplings at 20 pounds each for my offset – but wait! Passengers are also responsible for a portion of the carbon cost of the plane and it’s lifelong operation – because airlines wouldn’t buy airplanes if they couldn’t break even on their costs. So it’s not just about that one plane ride but each passenger’s share of the airplane’s entire existence and operation.

44,500,000 gallons x 20 lbs of carbon = 890,000,000 lbs of carbon produced to break even on the cost of the plane. That doesn’t include the carbon cost of mining the raw materials and manufacturing the plane. Rather than buy a 747 for 228 million in 2007, let’s say I spend my money on 408 million gallons of jet fuel at $1.79/gallon (priced today at The International Air Transport Association) and burn it. That’s another 8,162,400,000 lbs of carbon. Depending on all the details of manufacture, the plane’s carbon cost might have been much more or less than 9 billion pounds.  Whatever, let’s say 2 billion.

2 billion pounds divided by 2500 flights = 800,000 pounds / flight. 800,000 pounds /400 passengers = 2,000 pounds / passenger. Every flight of 3500 miles means 2,000 pounds of carbon per passenger or .5 pounds of carbon/mile. California to Hawaii is about 2500 miles so that would be 1250 pounds – if I flew.

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2 Responses to On jets

  1. Kai says:

    Hey Dan,

    Somebody needs to check the math and/or facts here. There is no way that a 6-7 pound gallon of jet fuel can generate 20 pounds of carbon… Also the “Boeing 747: mpg = 5”, how is that derived? Is that the per passenger mpg?

    Cheers! ~Kai

  2. Kai says:


    From Boing’s ‘747 Fun Facts’ link you have listed it says, “A 747-400 that flies 3,500 statute miles (5,630 km) and carries 126,000 pounds (56,700 kg) of fuel will consume an average of five gallons (19 L) per mile.” According to my math a 747 with 400 people on board consuming 5 gallons a mile for 3.,5000 miles works out such that if each person got into their own car and drove the same distance the cars would average out to 43.75 miles per gallon of each of the 400 cars. I’m not sure what the fuel rating of the average car in the US is but I would think it’s less than 43.75 mpg. Also the combined carbon footprint of the manufacture of all those cars, as well as tires, oil, cheeseburgers and road maps consumed would be considerably more than the manufacture of the 747.

    Not to brag or anything, but on ‘Desire’s 2,800 mile (2,400 miles as the plane flies) voyage to Hawaii I consumed 12 gallons of #2 diesel fuel and about 80 cans of stew, soup, tuna, anchovies, fruit, veggies and juices as well as 24 gallons of fresh water, 20 lbs beans and pasta, 28 energy bars, 7 MRE’s and the last (1) bottle, known to our family, of Schwarzenberg Pinot Noir.

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