14 CFR 23.145 - Longitudinal control.
(a) With the airplane as nearly as possible in trim at 1.3 VS1, it must be possible, at speeds below the trim speed, to pitch the nose downward so that the rate of increase in airspeed allows prompt acceleration to the trim speed with -
(1) Maximum continuous power on each engine;
(2) Power off; and
(3) Wing flap and landing gear -
(i) retracted, and
(b) Unless otherwise required, it must be possible to carry out the following maneuvers without requiring the application of single-handed control forces exceeding those specified in § 23.143(c). The trimming controls must not be adjusted during the maneuvers:
(1) With the landing gear extended, the flaps retracted, and the airplanes as nearly as possible in trim at 1.4 VS1, extend the flaps as rapidly as possible and allow the airspeed to transition from 1.4VS1 to 1.4 VSO:
(i) With power off; and
(ii) With the power necessary to maintain level flight in the initial condition.
(2) With landing gear and flaps extended, power off, and the airplane as nearly as possible in trim at 1.3 VSO: quickly apply takeoff power and retract the flaps as rapidly as possible to the recommended go around setting and allow the airspeed to transition from 1.3 VSO to 1.3 VS1. Retract the gear when a positive rate of climb is established.
(3) With landing gear and flaps extended, in level flight, power necessary to attain level flight at 1.1 VSO, and the airplane as nearly as possible in trim, it must be possible to maintain approximately level flight while retracting the flaps as rapidly as possible with simultaneous application of not more than maximum continuous power. If gated flat positions are provided, the flap retraction may be demonstrated in stages with power and trim reset for level flight at 1.1 VS1, in the initial configuration for each stage -
(i) From the fully extended position to the most extended gated position;
(ii) Between intermediate gated positions, if applicable; and
(iii) From the least extended gated position to the fully retracted position.
(5) With power off, landing gear and flaps extended, and the airplane as nearly as possible in trim at VREF, obtain and maintain airspeeds between 1.1 VSO, and either 1.7 VSO or VFE, whichever is lower without requiring the application of two-handed control forces exceeding those specified in § 23.143(c).
(6) With maximum takeoff power, landing gear retracted, flaps in the takeoff position, and the airplane as nearly as possible in trim at VFE appropriate to the takeoff flap position, retract the flaps as rapidly as possible while maintaining constant speed.
(c) At speeds above VMO/MMO, and up to the maximum speed shown under § 23.251, a maneuvering capability of 1.5 g must be demonstrated to provide a margin to recover from upset or inadvertent speed increase.
(d) It must be possible, with a pilot control force of not more than 10 pounds, to maintain a speed of not more than VREF during a power-off glide with landing gear and wing flaps extended, for any weight of the airplane, up to and including the maximum weight.
(e) By using normal flight and power controls, except as otherwise noted in paragraphs (e)(1) and (e)(2) of this section, it must be possible to establish a zero rate of descent at an attitude suitable for a controlled landing without exceeding the operational and structural limitations of the airplane, as follows:
(1) For single-engine and multiengine airplanes, without the use of the primary longitudinal control system.
(2) For multiengine airplanes -
(i) Without the use of the primary directional control; and
(ii) If a single failure of any one connecting or transmitting link would affect both the longitudinal and directional primary control system, without the primary longitudinal and directional control system.