If you Spitfire won't go over 200 mph IAS in straight level flight, check that the throttle (MAP) is set to maximum. The RPM can make 3000 at most any throttle setting. Also make sure your gear is up, you aren't carrying drop tanks, bombs, and/or rockets, and that the plane is trimmed.
The "big hand" on the airspeed indicator shows IAS or Indicated Air Speed. This is the speed that your control surfaces react to and varies with altitude (air density). The smaller red marker on the airspeed indicator shows TAS or True Air Speed which is the actual speed of the plane through the air. In our windless (at the moment) AH environment, TAS is also equal to ground speed. So, if you are trying to compute your time to destination, you should use TAS.
popeye
