Fuel Flow in a 747-400
 

This came up in the cockpit the other day and was asked by a jumpseater. He wanted to know what the FF was at cruise for a 747-400. I had no idea but it got us wondering. I was thinking it would be around 20-25000 pounds per hour as I'm just doubling the FF of a 767 since they share the same engine. Any thoughts? Thanks.

Been a while....
 

Takeoff was about 65k total, and on pond-crossings, I think first two hours of cruise were about 40-45k, decreasing about 2k an hour after that, so that at top of descent, you were looking at the 35-40k range.

But this is after 7 years, so I may be off a bit.

After a max gross weight takeoff with full tanks, the first hour in stabilised cruise at FL280 M.85 will have a fuel flow of about #30,000 decreasing by about #1,000 per hour, assuming you get cleared for optimum altitudes as you burn off fuel. So at the end of 16 hours at cruise you will only be burning #14,000-15,000 per hour, and by 17 hours your fuel flow will be zero.

Joe

Thanks all. Does anyone know what a 777 burns? I'm just curious if the 777-300 is much more efficient over the 747.