Sec. 23.175 - Demonstration of static
longitudinal stability.
Static longitudinal stability must be shown as follows: (a) (1) Flaps retracted; (2) Landing gear retracted; (3) Maximum continuous power; and (4) The airplane trimmed at the speed used in determining the climb performance required by §23.69(a). (b) (1) For normal, utility, and acrobatic category airplanes, the stick force curve must have a stable slope at all speeds within a range that is the greater of 15 percent of the trim speed plus the resulting free return speed range, or 40 knots plus the resulting free return speed range, above and below the trim speed, except that the slope need not be stable -- (i) At speeds less than 1.3 V (ii) For airplanes with V (iii) For airplanes with V (2) For commuter category airplanes, the stick force curve must have a stable slope at all speeds within a range of 50 knots plus the resulting free return speed range, above and below the trim speed, except that the slope need not be stable -- (i) At speeds less than 1.4 V (ii) At speeds greater than V (iii) At speeds that require a stick force greater than 50 pounds. (c) (1) Flaps in the landing position; (2) Landing gear extended; and (3) The airplane trimmed at -- (i) V (ii) V [Doc. No. 27807, 61 FR 5190, Feb. 9, 1996] |