Thorp Air Command - T18.net

I just received my Tech Counselor newsletter and one topic was the aft CG. Seems Cessna has a similar problem when loaded with four passengers, baggage and low fuel. The pilot was landing and noticed that at 55knts approach speed he ran out of elevator. He increased his approached speed and made a good landing.
Calculations for horizontal tail coefficient;

HTC=(horizontal tail area x tail arm) / (wing area x wing cord)

"The tail arm should be taken from the mean position to the CG. Wing cord is mean cord. For most aircraft this comes out 0.3 to 0.7. The higher coefficient, the more elevator authority you have. If you are landing on the low side, take precautions by avoiding far aft baggage."

"A flight test can be done with 20-25% fuel and more baggage weight behind the seat. You should select a final approach speed on the high side, 1.3 to 1.4 times landing configuration stall speed". There has been several discussions about the Thorp being difficult to land with aft CG.

Maybe this is the answer......