Section 25.399 - Dual control system(a) Each dual control system must be designed for the pilots operating in opposition, using individual pilot forces not less than-(1) 0.75 times those obtained under § 25.395 ; or(2) The minimum forces specified in § 25.397(c) .(b) The control system must be designed for pilot forces applied in the same direction, using individual pilot forces not less than 0.75 times those obtained under § 25.395 .