"Mxsmanic" wrote in message Do you often need a different altitude from
the one you filed?
Perhaps for fuel considerations, or headwinds, or something?

Often times our actual weight will be slightly different from the flight
planned weight requiring 2000' up or down for fuel optimization. Turbulence
is another reason to change altitudes, sometimes 10000' or more. A 2000'
change in altitude usually doesn't make enough difference in headwinds to
justify the increased fuel burn of changing altitudes. Sometimes we are just
plain stuck at an inefficient altitude because of same direction traffic.

So what do they say in this telephone call?

Along the lines of 'Now you know- don't do it again".

I would have thought that altitude and track would both be about
equally important.

They are both important, however altitude leeway is +/-300' whereas airways
have .5 to 4 miles of leeway.

D.