S-67 Aircraft Feel Agumentation System Flight Evaluation

A flight test program has been conducted to evaluate improvements in handling qualities of the S-67 resulting from the addition of a Feel Augmentation System FAS. The pitch channel of FAS applies to the cyclic stick a force proportional to the load factor resulting from aircraft pitch rate. Roll FAS provides control harmony, and the collective stick shaker warns of high rotor control loads. Subjective reactions of contractor test pilots, combined with flight test results, indicated that a satisfactory load factor force gradient was 18-25 pounds per g. Furthermore, this nearly constant force gradient was insensitive to changes in airspeeds, collective setting, or attitude during maneuvers.