What is the MPG on a commercial jet?

Question

if it's measured in lbs/hr there has to be a calculation of what a lb= to?

Answer 1

The airplane I fly burns about 1400 pounds an hour in cruise flight. Thats about 200 gallons per hour.  It cruises at about 250 mph.  By my math, that works out to 1.2 mpg. in cruise flight. You burn more during take-off run, during climb out. But you burn less during the descent because the power is pulled back.

Of course, for the 1.2 mpg, we carry 30-50 people and bags. For 40,000 lbs going through the air at 250 mph, thats pretty efficient.

Thats not considering headwind or tailwind. With a good tailwind, we'll burn the same amount of fuel, but travel farther with it. Unfortunately, we have headwinds, which have the opposite effect.

Thats with a turboprop, a jet engine driving a propeller.Pure jets burn much more then that. So, yeah, 48k for fuel sounds right.

The problem with hydrogen is the conversion process. By that, I mean converting todays technology to run on hydrogen. Airplanes are very weight sensitive, you can only take so much weight into the air in regards to the airframe design.

For aircraft to run on hydrogen, there'd have to be a way to keep it on-board, keep it safe, fire suppression for emergency, fire consideration for a crash,etc.  Engines would have to be designed to run hydrogen. All this would add weight, which would reduce payload capacity.  

You'd need an airplane that was a clean-sheet design, this would cost billions in R&D, something the manufacturers know that todays cash-strapped airlines would not pick-up the cost for.

Hydrogen in cars is 5-10 years away at best, right now. Airplanes, double that?

Answer 2

A Mooney Bravo will do about 12-15 MPG depending on load and cruise altitude.

A trip average would give you about 12gal/hour, at an average speed of about 150kts (ground speed, including climb, cruise, descent and approach, normal power settings, no wind).

It's not a commercial jet, but I beleive the airliners will give you roughly a similar ratio of fuel per passenger

Answer 3

MPG is the wrong way to think about it. Better would be GPM. And yes, 48 large to fly NY-MIA sounds about right for the fuel ticket. Glad I got out of all my airline stocks.

Answer 4

US aircraft measure fuel consumption in lbs/hr, AFAIK

Answer 5

A B727 gets about 1/3 mile per gallon.

A gallon is about 6.7 lb.

A gallon is around US$4.

Answer 6

Friedach is correct. It is hard to measure the distance per gallon of Jet A fuel. Because there really is not a constant. You must account for winds, on the ground and aloft, weight, the amount of drag the aircraft produces (aerodynamic), and power settings the plane uses in cruise flight. Jet A fuel weighs 6.84lbs/gal.

According to British Airways, a 747-400 plane cruises at 576 mph, burns 3378 US gallons of fuel per hour, and carries 409 passengers when full.

Answer 7

I am not sure if this is helpful, but I saw site that compares MPG of different car types, and it had Boeing 747 as one of the choices.  The site is at MuzzleYourGuzzle.com.  It allows you to calculate the cost of a trip.  (i.e. how much would it cost - in terms of gasoline - to get to your work?)

Answer 8

It can vary greatly, but if you divide the fuel burn by the amount of passengers then they get anywhere from 60-100mpg per person.