These are the principles of the calculations:
Plane: This describes the nomenclature of the particular plane, including it's nickname or common name
Weight (Empty/Loaded/Max): The weights of the plane when empty, when at typical combat weight, and maximum takeoff weight.
Wing Area: The area of the wings.
Wing Loading: For each of the planes weights, the wing loading is derived from dividing the weight by the wing area. It is broken into three numbers, the first being the empty plane wing loading, the second the typical combat weight, the third being maximum takeoff weight. Wing loading helps in instantaneous turns, and sustained turns. A low wing loading allows a higher g load on the plane at a particular speed.
Engine: Describes the horsepower of the engine (base, no WEP), the maker of the engine, and whether it is a radial or inline (liquid cooled) engine. Radial engines tend to take more battle damage before failing.
Flaps: The number of possible settings for the flaps
Visibility: My judgement of visibility conditions for front view, side view, and rear view. This field is only used if a plane has its own art, otherwise it refers to the plane whose art is used.
Control feel: My judgement of control feel for the plane's elevators, rudder and roll (ailerons) at slow speeds (near stall), near the sustained maximum speed of the plane, and above the maximum speed of the plane (fast).
Stall speed: 10 minutes worth of fuel loaded on the plane, the speed the stall horn start kicking in with/without flaps to maintain level flight.
Guns: Table containing the gun type, caliber, rate-of-fire(ROF), firing time (duration), Warbirds' ping "punch", muzzle velocity, and ammunition supply/gun, broken down by primary and secondary banks of weapons.
Ordnance: Breakdown of the ordnance loadouts for ordnance settings of 0-3
Fuel Time/Percent: Time that the engine ran at full power with 1% gas loaded
Power/Weight (Empty/Loaded/Max): The plane's weight divided by the base horsepower of the engine. A rough measure of a plane's acceleration and climbing ability, as well as diving ability to some degree. Lower is better.
Corner Velocity: The speed at which the screen starts to become visible again when pulling a maximum-g turn from 350mph. Somewhat useful for determining instantaneous turn rate. Very useful for TnB fights since this is the maximum speed at which you can turn minimum radius, while at the same time, the minimum speed at which you can pull max G. It is also the point at which your plane is capable of maximum turn rate along that radius, and this turn rate slows down to sustained turn rate levels as speed is bled off (usually quickly).
Durability: My judgement of the plane's ability to take gunfire before falling apart.
WEP time: Duration of WEP, if the plane has WEP
Plane's Maximum Angle-of-Attack (no flaps/full flaps): Plane's Angle-of-Attack determined by AoA study
Plane's wing effective Incidence Angle (no flaps/full flaps): Plane's wing effective incident angle to fuselage, determined by AoA study
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As I stated, I only re-worked the ROC and the ceilings, but the source book I referred to will allow all of the above to be calculated as the book contains detailed specs on weights and horsepower.
It just depends on how far you want to go.
This page shows the already worked up performance specs on some of the more popular WW2 aircraft, (to use as an example of how far in detail you might go:
http://www.rdrop.com/users/hoofj/index.html
Yes, that is one of unknowns.