B773 fuel consumption?
 

Hi,

I was just trying to calculate - in a "ballpark" way - the hourly fuel consumption for the 773; this is part of an exercise to try and determine the most economical aircraft for a long haul/low cost operation - purely for personal interest and not part of any commercial venture.

According to figures available to me, the 772 burns about 14,600lbs (or 6,500kgs) per hour and based on figures I've worked out so far, the 773 should have a fuel consumption of about 17-17,500lbs (or c.7,500kgs) per hour, to be close in efficiency to the 748I - which looks - according to projected figures - to be considerably more economical than the 380.

I appreciate (a) that it's a "how long is a piece of string" question to a certain extent - but let's just assume FL350 cruise and (b), there are issues of company confidentiality, but really all I'm looking for is a "feel" for how the 773 compares; as the largest twin engined aircraft available, I'd expect it to be among the most fuel efficient acft, per seat, available.

Many thanks for any help you can provide.

Re: B773 fuel consumption?
 

Just been told by a 777 driver, per hour 6T - light weight, 7T - med weight & 7.5T at the most heavy weight.

Re: B773 fuel consumption?
 

Many thanks indeed, SMOC; that's actually at the lower end of what I'd been expecting. It's certainly a very economical aircraft!

Re: B773 fuel consumption?
 

This off a recent flight in a -300ER. 617 air miles we burned 13 tonnes, flight time of 1:26. TOW was 262.1 tonnes, landing very near MLW.

The book shows a cruise burn of: 8.7 tonnes per hour at 300 tonnes, FL 330
7.0 tonnes per hour at 240 tonnes, FL 350

For a 4000 mile mission in zero wind conditions you are looking at 8.3 tonnes an hour on average for a landing at MLW. If you were 50 tonnes lighter on the same mission you would burn 6.8 tonnes an hour on average. SMOC must have got his info from a 777-200 driver because those are the figures for that aircraft.

Hope that helps,

Typhoonpilot

Re: B773 fuel consumption?
 

I'll ask him again.

And I did, found out the CX -300s are limited to a MTOW of 263T so this accounts for the low fuel burn at "heavy weight"