Malaysian Airlines MH370 contact lost

[RatherBeFlying]

In the hope of reducing the quantity of posts here on range and speed, it may be helpful to summarise from D. P. Davies Flying the Big Jets as best my fading memory permits:

1. Fuel consumption in a jet at cruise does not much change with altitude
2. True Airspeed is substantially greater at cruise altitudes than lower down
3. i.e. at cruise altitudes you get substantially more nautical miles per pound of fuel

The alleged low level sector to past Banda Aceh used substantially more fuel than if it had been done at FL350, leaving less fuel for the Southbound leg.

Obviously somebody has worked through the performance charts (or plugged the numbers into the computer program) to derive a new expected range from the last suspected turnpoint and has plotted that to the final ping arc -- and has incorporated the uncertainties to produce a search area.