50+Ray, that website is about the T3a not the Firefly.
The US Air Force's T-3A was derived from the Slingsby Aviation T67M260 Firefly. Slingsby is an England based company which has been building small aircraft since the 1970's. The T-3A has several differences from the T67M260 including the addition of air conditioning and a smaller rudder.
I decided to weigh the aircraft anyway. I put a T-3 on the scales with full wing tanks and oil, plus me and a cadet in the seats with our parachutes on with the canopy closed--exactly the situation for a normal takeoff. The aircraft was scaled inside a hangar with a known level floor. The weights at all three wheels were taken and the numbers crunched. We were over two inches rear of the rear CG limit! I tried to push this info up the chain of command but because the aircraft wasn't leveled to Slingsby's specification (whatever that was) no one believed the numbers. I know that leveling the aircraft will move the CG but there's no way it was going to shift the CG two inches forward--you'd have to stand the aircraft on it's freakin' nose to do that. The bottom line is we were flying the aircraft with an extremely aft center of gravity and no one wanted to admit it.
Big and Small Rudder
Some T67 Fireflies have a "big rudder" while all T-3A's have a "small rudder." Here's a pic of the two rudders for comparison:
Note how bottom edge of the T67 "big rudder" (left photo) follows the angle of the bottom of the empennage and so has about two inches of rudder below the trailing edge position light. The T-3A on the right has a smaller rudder that angles up to the position light.
If we estimate the bottom length of the rudder to be 14 inches that gives us: (14 x 2) / 2 = 14 square inches. Fourteen square inches of additional rudder that's in the best possible location--mostly at the trailing edge below the elevator in clean airstream during a spin. If I owned a T67 with the small rudder I'd look into replacing it with the larger rudder.
I'm not sure that everyone reading this gets the differences between the T67 & the T3, but it's interesting that the crash aircraft from last week has a small rudder.