I looked into RAM values and such, to find the exact HP & damage numbers.

https://docs.google.com/spreadsheets/d/15TUDsbBowHTZeu27guE8upV944I3-fT0NdOg7JzDZbQ/edit?usp=sharing

Summary:

• Most planes have the same top speed (1188 mph), although there are some planes with different acceleration. The Mirage & F-14 have faster then average accel, while the X-02 & Typhoon are slower then average.
• The MIG-31 is the fastest plane by far (1296 mph). The J-35 has the same top speed, but it's acceleration is noticeably worse.
• Every plane's gun I've tested has the same damage & rate of fire.
• The gun does 12 damage per hit, standard missiles do 40.
• Certain enemies have special resistances. For example: Boss aces generally have 80 hp, and most SP A2A missiles do 80 damage, but aces only take 40 damage. Certain ground targets also only take 1 damage from the gun (the CTRL Tower in M07 & Excalibur in particular).

I got the idea of doing all this from the data on Mitoro's site. The data for AC5 is pretty similar, so you can view that here: http://www.ne.jp/asahi/mitoro/page/ac5/data/performance.htm