Fuel consumption of jet engine? Gallons per hour?

Question

What is the fuel consumption of a Pratt & Whitney JT8D jet engine, in gallons per hour or pounds per hour? It's the engine from the old Boeing 727's and pre-1981 737's, among others. The SAAB Gripen fighter used an engine derivative.

I was thinking about a small, supersonic airplane capable of flight with 2-4 passengers. Some newer fighters are capable of supercruise (non-afterburning superburning flight, to save fuel and extend range). They also have gun and bomb loads, redundant systems, radars, great visibility, carrier ops equipment, very high strength, extreme maneuverability, etc... Everything else these airplanes need to do adds weight, cost, and aerodynamic drag. Removing those requirements and concentrating on efficiently going fast sounds easy. I like the JT8D since it's powerful enough to push airliners and would be the able to do this while only being a single engine airplane, yet has great parts availability and cheap initial cost. Dreaming up an airplane design is fun. (I know, I'm a dork! GRINS) I just need to know how much fuel they burn, in order to design around it. Knowing both the sea-level, max power takeoff thrust fuel consumption and high altitude (at least 40,000 feet) cruise thrust fuel consumption would help. Thanks!

Anonymous · Accepted Answer

Average block fuel burn for the JT8D-217C or -219 engines on the MD80 is 6500 lb/hour, which with fuel weighing 6.7 lb/gallon is about 1000 gallons per hour, or 500 GPH per engine.

Gertrude · Answer

Dan - Check your math 3000 lb / 7 is 428 gals - 1 gal of jet fuel is a bit under 7 lbs 
Your math is off 18000 gals per hour  x 5 hour cross country flight would 90000 gals of fuel
the weight of the fuel 630,000 lbs alone  (and only military air-force C5 SG &  Boeing 747-8, 
 Super heavy lift air craft  can take off w/ that load  747-8 has a total weight take off 987,000
(that includes plane - fuel - cargo pilots - every thing) Have heard that 747-8 has taken off with tw of 1,000,000 lbs  (best  in the world)

Dan B · Answer

Jet engines use pounds per hour (PPH) instead of gallons per hour because using consumption as gallons per hour would result in high numbers.  3000 lbs per hour is the same as about 18,000 gallons per hour.  Also, pounds of fuel on board a jet is easier to use for weight and balance calculations before takeoff and while in flight.  Another reason is a pound of fuel is a pound of fuel regardless of unit of volume measure (imperial or metric).

Warbird Pilot · Answer

About 3000 pounds an hour (divide by 6 or so).  Jet consumption is generally in PPH because the specific gravity can change with temperature over the operating altitudes.

JT8D was a hell of an engine.

Mark · Answer

3000 pounds per hour in cruise.

? · Answer

not sure on how much they use, i just know that it's not really gallons per hour, its more like gallons per minute. they burn several gallons a minute, not sure on an exact number tho.

the terminator · Answer

sorry depends how fast your going 
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Fuel consumption of jet engine? Gallons per hour?

7 Answers