as a note to the various "ceilings" aircraft could operate at.
Please note that the following ceilings were usually figured out for "normal" gross weight (as in
clean condition)
Absolute ceiling, almost always calculated based of the climb rates at lower ceilings. The was theoretical ceiling the plane could reach at full throttle (or max continuous power) and maintain for at least a few minutes. No zoom climb
Service ceiling, the altitude a plane could still climb at 100fpm (or metric equivalent) while using standard climb power setting/rpm. Please note that going above this altitude to try for absolute ceiling is going to tanke many minutes as the climb rate falls into the low double digit per minute range.
Operational Ceiling. Seldom listed and may be a British term. At any rate it is the ceiling at which the plane could still climb at 500fpm (or metric/air force in question equivalent). this was to allow for variations between planes in a
small formation and for the worst plane to be on the outside of a turn. It was highest ceiling the planners thought the small formation could maneuver at and still keep formation.
Combat Ceiling, Again seldom listed and again may be British. It is the max ceiling at which the British figured a fighter could engage in combat (aside from a pure diving attack??) with enough surplus power for at least some combat maneuvers.
Please note that absolute and Service ceiling are near useless for figuring out combat capabilities except as a very rough benchmark. A Spitfire V could take 20 minutes to make it to about 35,500 and it took 4 of those minutes to climb the last 2000ft.
Some planes had the climb rate fall off faster than others.
