San Francisco, USA to Heathrow London, UK

hi guys flying from KSAF to EGLL, flying in a 747-400 Been flying for 39 minutes got to my cruising altitude of FL340 and cruising at 300knots. Have 328 passengers on board, 30,000lbs of cargo and full fuel-load. Few questions... whats best cruising speed+altitude for the 747? How much fuel will i be looking at using during the flight 4500nm or something? What is everyone else upto at this moment in time?

Determining your cruising altitude is governed by a number of things.

How much below maximum kias are you at specific flight levels, actual ground speed and winds aloft.

You can bring it up another couple of thousand feet, but watch your instrument panel so that you don't exceed maximum kias or turbine temps. You might pick up some ground speed that way. Also, toggle through shift-z to see what your winds look like and take advantage of the greatest til wind/least headwind.

Just safley touched down in Heathrow after a missed first approach. I ended up cruising at FL340 and 330kias.

Firts time ive actually landed a 747 succesfully and im really proud as i touched down with the smoothest landing ive done all the time ive been palying flight sim.

Congratulations. The 747 is a handful.