B747 Relief Pilot reports departing with an estimated arrival fuel of 22;500 pounds. Flight burned 2500 pounds extra enroute and an additional 3500 during arrival; resulting in landing with 16500 pounds of fuel.

Narrative

I was one of two relief pilots and on the bus ride to the airport; the Captain requested the other RP and I to proceed directly to the airplane; as he felt that we would be pressed for time. This essentially kept us out of the loop for flight planning (had we known he would accept 22.5 as arrival fuel; we almost certainly would have requested more fuel). The flight proceeded initially without any real problems; except that by the time we relieved the flying pilots; we were down approximately 2500 LBS on fuel. We were briefed to fly the TAS on the Flight Plan; even though this did not correlate with the ECON speeds from the FMC (we adjusted the Cost Index; as per our training and the related Bulletin). We were also told to fly the altitudes on the flight plan; which were consistently 2;000 FT lower than what the bulletin recommends. The fuel score continued to deteriorate (and the winds were somewhat worse than forecast); so we climbed early from FL350 to FL370. This didn't help at all; and when we received a report of turbulence ahead at FL370 we elected to descend back to FL350. On this leg; even though the winds were now around 10K more favorable; and we descended 2000 FT; we still lost another 500 LBS; so we were 4000 LBS low at that point. Slowly the fuel started to improve so that by the time we approached destination we were only about 2500 low. Unfortunately; they were landing to the west; and their low-and-slow handling cost us probably at least another 2500 LBS; so that we landed with approx. 16;500 LBS...6000 LBS less than planned. There was no apparent reason why we should have been so far down on the fuel; unless either the flight plan itself was flawed; or we were heavier than we thought.