14 CFR § 27.397

Except as provided in paragraph (b) of this section, the limit pilot forces are as follows:

For foot controls, 130 pounds.

For stick controls, 100 pounds fore and aft, and 67 pounds laterally.

For flap, tab, stabilizer, rotor brake, and landing gear operating controls, the follows apply (R = radius in inches):

Crank, wheel, and lever controls, [1 + R]/3 × 50 pounds, but not less than 50 pounds nor more than 100 pounds for hand operated controls or 130 pounds for foot operated controls, applied at any angle within 20 degrees of the plane of motion of the control.

Twist controls, 80R inch-pounds.