Optimum Altitude

[George Yogi]

Optimum Altitude :-
Altitude at which a/c covers max distance per kg fuel burnt.
Optimum altitude depends on Actual wt and deviation from ISA.

Does that mean optimum altitude keeps on changing with wt change in a/c due fuel burn and ISA conditions ? , Does FMGS contunually calculate both these parameters and keep on suggesting step climbs ?
How do airline manage this scenario to save fuel ?

[RTN11]

Yep, it's constantly changing, and without knowing the actual temperature at all levels it's almost impossible to find the true optimum altitude, you just go on the best forecast/trend of conditions.

The FMS will certainly be suggesting the best level, but ultimately you have to take what ATC can give you, and in busy airspace the optimum level isn't always available.

Add to that the fact that the wind can change dramatically in 1000', you tend to take that into account a lot more and just make a judgement based on experience as to what will be best.

[George Yogi]

Interesting
Thanks RTN11

[framer]

Many pilots keep a close eye on the winds in the last few thousand feet to make sure there isn't a more economical FL just below their chosen level.