When will people get it in their noggin that a 777-200 WILL NOT achieve, let alone "cruise" at FL450.
There has never been any accurate nor reliable indication as to MH370 climbing to FL450. Primary radar can only roughly approximate aircraft altitude from slant angle and range. And as for the question:
2 Trent's operating at max continuos, clawing at the sky trying to attain FL450 tend to consume fuel at a prodigious rate compared to a cruise power setting at the optimum FL ......
