Code of Federal Regulations - Title 14

204

14 CFR Ch. I (1–1–14 Edition)

§ 23.201

controls in both free and fixed position,
must be damped to

⁄

amplitude in:

(1) Seven (7) cycles below 18,000 feet

and

(2) Thirteen (13) cycles from 18,000

feet to the certified maximum altitude.

tion of a stability augmentation sys-
tem, reference § 23.672, is needed to
meet the flight characteristic require-
ments of this part, the primary control
requirements of paragraphs (a)(2) and
(b)(2) of this section are not applicable
to the tests needed to verify the ac-
ceptability of that system.

(d) During the conditions as specified

in § 23.175, when the longitudinal con-
trol force required to maintain speeds
differing from the trim speed by at
least plus and minus 15 percent is sud-
denly released, the response of the air-
plane must not exhibit any dangerous
characteristics nor be excessive in rela-
tion to the magnitude of the control
force released. Any long-period oscilla-
tion of flight path, phugoid oscillation,
that results must not be so unstable as
to increase the pilot’s workload or oth-
erwise endanger the airplane.

[Amdt. 23–21, 43 FR 2318, Jan. 16, 1978, as
amended by Amdt. 23–45, 58 FR 42158, Aug. 6,
1993; Amdt. 23–62, 76 FR 75755, Dec. 2, 2011]

TALLS

§ 23.201

Wings level stall.

(a) It must be possible to produce and

to correct roll by unreversed use of the
rolling control and to produce and to
correct yaw by unreversed use of the
directional control, up to the time the
airplane stalls.

(b) The wings level stall characteris-

tics must be demonstrated in flight as
follows. Starting from a speed at least
10 knots above the stall speed, the ele-
vator control must be pulled back so
that the rate of speed reduction will
not exceed one knot per second until a
stall is produced, as shown by either:

(1) An uncontrollable downward

pitching motion of the airplane;

(2) A downward pitching motion of

the airplane that results from the acti-
vation of a stall avoidance device (for
example, stick pusher); or

(3) The control reaching the stop.
(c) Normal use of elevator control for

recovery is allowed after the downward

pitching motion of paragraphs (b)(1) or
(b)(2) of this section has unmistakably
been produced, or after the control has
been held against the stop for not less
than the longer of two seconds or the
time employed in the minimum steady
slight speed determination of § 23.49.

(d) During the entry into and the re-

covery from the maneuver, it must be
possible to prevent more than 15 de-
grees of roll or yaw by the normal use
of controls except as provided for in
paragraph (e) of this section.

(e) For airplanes approved with a

maximum operating altitude at or
above 25,000 feet during the entry into
and the recovery from stalls performed
at or above 25,000 feet, it must be pos-
sible to prevent more than 25 degrees of
roll or yaw by the normal use of con-
trols.

(f) Compliance with the requirements

of this section must be shown under
the following conditions:

(1)

Wing flaps: Retracted, fully ex-

tended, and each intermediate normal
operating position, as appropriate for
the phase of flight.

(2)

Landing gear: Retracted and ex-

tended as appropriate for the altitude.

(3)

Cowl flaps: Appropriate to configu-

ration.

(4)

Spoilers/speedbrakes: Retracted and

extended unless they have no
measureable effect at low speeds.

(5)

Power:

(i) Power/Thrust off; and
(ii) For reciprocating engine powered

airplanes: 75 percent of maximum con-
tinuous power. However, if the power-
to-weight ratio at 75 percent of max-
imum continuous power results in
nose-high attitudes exceeding 30 de-
grees, the test may be carried out with
the power required for level flight in
the landing configuration at maximum
landing weight and a speed of 1.4 V

except that the power may not be less
than 50 percent of maximum contin-
uous power; or

(iii) For turbine engine powered air-

planes: The maximum engine thrust,
except that it need not exceed the
thrust necessary to maintain level
flight at 1.5 V

(where V

corresponds

to the stalling speed with flaps in the
approach position, the landing gear re-
tracted, and maximum landing weight).

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