Federal Aviation Administration, DOT § 23.203

STALLS may not be less than 50 percent of max- imum continuous power. § 23.201 Wings level . (5) Trim. The airplane trimmed at a (a) It must be possible to produce and speed as near 1.5 VS1 as practicable. to correct roll by unreversed use of the (6) Propeller. Full increase r.p.m. posi- rolling control and to produce and to tion for the power off condition. correct yaw by unreversed use of the [Doc. No. 27807, 61 FR 5191, Feb. 9, 1996] directional control, up to the time the airplane stalls. § 23.203 Turning flight and accelerated (b) The wings level stall characteris- turning stalls. tics must be demonstrated in flight as Turning flight and accelerated turn- follows. Starting from a speed at least ing stalls must be demonstrated in 10 knots above the stall speed, the ele- tests as follows: vator control must be pulled back so (a) Establish and maintain a coordi- that the rate of speed reduction will nated turn in a 30 degree bank. Reduce not exceed one knot per second until a speed by steadily and progressively stall is produced, as shown by either: tightening the turn with the (1) An uncontrollable downward until the airplane is stalled, as defined pitching motion of the airplane; in § 23.201(b). The rate of speed reduc- (2) A downward pitching motion of tion must be constant, and— the airplane that results from the acti- (1) For a turning flight stall, may not vation of a stall avoidance device (for exceed one knot per second; and example, stick pusher); or (2) For an accelerated turning stall, (3) The control reaching the stop. be 3 to 5 knots per second with steadily (c) Normal use of elevator control for increasing normal acceleration. recovery is allowed after the downward (b) After the airplane has stalled, as pitching motion of paragraphs (b)(1) or defined in § 23.201(b), it must be possible (b)(2) of this section has unmistakably to regain wings level flight by normal been produced, or after the control has use of the flight controls, but without been held against the stop for not less increasing power and without— than the longer of two seconds or the (1) Excessive loss of altitude; time employed in the minimum steady (2) Undue pitchup; slight speed determination of § 23.49. (3) Uncontrollable tendency to spin; (d) During the entry into and the re- (4) Exceeding a bank angle of 60 de- covery from the maneuver, it must be grees in the original direction of the possible to prevent more than 15 de- turn or 30 degrees in the opposite direc- grees of roll or yaw by the normal use tion in the case of turning flight stalls; of controls. (5) Exceeding a bank angle of 90 de- (e) Compliance with the require- grees in the original direction of the ments of this section must be shown turn or 60 degrees in the opposite direc- under the following conditions: tion in the case of accelerated turning (1) Wing flaps. Retracted, fully ex- stalls; and tended, and each intermediate normal (6) Exceeding the maximum permis- operating position. sible speed or allowable limit load fac- (2) . Retracted and ex- tor. tended. (c) Compliance with the require- (3) Cowl flaps. Appropriate to configu- ments of this section must be shown ration. under the following conditions: (4) Power: (1) Wing flaps: Retracted, fully ex- (i) Power off; and tended, and each intermediate normal (ii) 75 percent of maximum contin- operating position; uous power. However, if the power-to- (2) Landing gear: Retracted and ex- weight ratio at 75 percent of maximum tended; continuous power result in extreme (3) Cowl flaps: Appropriate to configu- nose-up attitudes, the test may be car- ration; ried out with the power required for (4) Power: level flight in the landing configura- (i) Power off; and tion at maximum landing weight and a (ii) 75 percent of maximum contin- speed of 1.4 VSO, except that the power uous power. However, if the power-to- 215

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weight ratio at 75 percent of maximum SPINNING continuous power results in extreme nose-up attitudes, the test may be car- § 23.221 Spinning. ried out with the power required for (a) Normal category airplanes. A sin- level flight in the landing configura- gle-engine, normal category airplane tion at maximum landing weight and a must be able to recover from a one- speed of 1.4 VSO, except that the power turn spin or a three-second spin, which- may not be less than 50 percent of max- ever takes longer, in not more than one imum continuous power. additional turn after initiation of the (5) Trim: The airplane trimmed at a first control action for recovery, or speed as near 1.5 VS1 as practicable. demonstrate compliance with the op- (6) Propeller. Full increase rpm posi- tional spin resistant requirements of tion for the power off condition. this section. [Amdt. 23–14, 38 FR 31820, Nov. 19, 1973, as (1) The following apply to one turn or amended by Amdt. 23–45, 58 FR 42159, Aug. 6, three second spins: 1993; Amdt. 23–50, 61 FR 5191, Feb. 9, 1996] (i) For both the flaps-retracted and flaps-extended conditions, the applica- § 23.207 Stall warning. ble airspeed limit and positive limit (a) There must be a clear and distinc- maneuvering load factor must not be tive stall warning, with the flaps and exceeded; landing gear in any normal position, in (ii) No control forces or char- straight and turning flight. acteristic encountered during the spin (b) The stall warning may be fur- or recovery may adversely affect nished either through the inherent aer- prompt recovery; odynamic qualities of the airplane or (iii) It must be impossible to obtain by a device that will give clearly dis- unrecoverable spins with any use of the tinguishable indications under ex- flight or engine power controls either pected conditions of flight. However, a at the entry into or during the spin; visual stall warning device that re- and quires the attention of the crew within (iv) For the flaps-extended condition, the cockpit is not acceptable by itself. the flaps may be retracted during the (c) During the stall tests required by recovery but not before rotation has § 23.201(b) and § 23.203(a)(1), the stall ceased. warning must begin at a speed exceed- (2) At the applicant’s option, the air- ing the stalling speed by a margin of plane may be demonstrated to be spin not less than 5 knots and must con- resistant by the following: tinue until the stall occurs. (i) During the stall maneuver con- (d) When following procedures fur- tained in § 23.201, the pitch control nished in accordance with § 23.1585, the must be pulled back and held against stall warning must not occur during a the stop. Then, using and rud- takeoff with all engines operating, a ders in the proper direction, it must be takeoff continued with one engine in- possible to maintain wings-level flight operative, or during an approach to within 15 degrees of bank and to roll landing. the airplane from a 30 degree bank in (e) During the stall tests required by one direction to a 30 degree bank in the § 23.203(a)(2), the stall warning must other direction; begin sufficiently in advance of the (ii) Reduce the airplane speed using stall for the stall to be averted by pilot pitch control at a rate of approxi- action taken after the stall warning mately one knot per second until the first occurs. pitch control reaches the stop; then, (f) For acrobatic category airplanes, with the pitch control pulled back and an artificial stall warning may be mu- held against the stop, apply full table, provided that it is armed auto- control in a manner to promote spin matically during takeoff and rearmed entry for a period of seven seconds or automatically in the approach configu- through a 360 degree heading change, ration. whichever occurs first. If the 360 degree [Amdt. 23–7, 34 FR 13087, Aug. 13, 1969, as heading change is reached first, it must amended by Amdt. 23–45, 58 FR 42159, Aug. 6, have taken no fewer than four seconds. 1993; Amdt. 23–50, 61 FR 5191, Feb. 9, 1996] This maneuver must be performed first

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