Cruise alt.

[elite marksman]

Is there any easy way to calculate the optimum cruise setting without the aid of a FMC. I was thinking of writing a program for my TI-83+ to do it, but I'm not sure what things other than weight, and # and power of engines to consider.

[Rocket_Bird]

I don't think theres really an easy way to do it.  Every aircraft is different.  From different airframes to different powerplants.  Even temperature, weight, and pressure differences will affect the cruise settings on the aircraft.  Thats why manufacturers put cruise data into a chart for pilots to use, because every airframe/powerplant is unique.

Correct me if im wrong though, anyone

[beaky]

RB is right: no such thing as a universal formula, and for each type, a chart is required because it may depend on weight (and CG), temps, density altitude, etc.
Best way to go is to use the chart for the aircraft in question.

[Ivan]

that's where you have an FMC for... full autoflight, only thing the pilot has to do is watch out for atc errors and weather