Sec. 27.173 - Static longitudinal stability.
(a) The longitudinal control must be designed so that a rearward movement of the control is necessary to obtain a speed less than the trim speed, and a forward movement of the control is necessary to obtain a speed more than the trim speed.
(b) With the throttle and collective pitch held constant during the maneuvers specified in §27.175 (a) through (c), the slope of the control position versus speed curve must be positive throughout the full range of altitude for which certification is requested.
(c) During the maneuver specified in §27.175(d), the longitudinal control position versus speed curve may have a negative slope within the specified speed range if the negative motion is not greater than 10 percent of total control travel.
[Amdt. 27-21, 49 FR 44433, Nov. 6, 1984]