227
Federal Aviation Administration, DOT
§ 25.207
the pilot a clear and distinctive indica-
tion of an acceptable nature that the
airplane is stalled. Acceptable indica-
tions of a stall, occurring either indi-
vidually or in combination, are—
(1) A nose-down pitch that cannot be
readily arrested;
(2) Buffeting, of a magnitude and se-
verity that is a strong and effective de-
terrent to further speed reduction; or
(3) The pitch control reaches the aft
stop and no further increase in pitch
attitude occurs when the control is
held full aft for a short time before re-
covery is initiated.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–84, 60 FR 30750, June 9,
1995; Amdt. 25–108, 67 FR 70827, Nov. 26, 2002]
§ 25.203
Stall characteristics.
(a) It must be possible to produce and
to correct roll and yaw by unreversed
use of the aileron and rudder controls,
up to the time the airplane is stalled.
No abnormal nose-up pitching may
occur. The longitudinal control force
must be positive up to and throughout
the stall. In addition, it must be pos-
sible to promptly prevent stalling and
to recover from a stall by normal use
of the controls.
(b) For level wing stalls, the roll oc-
curring between the stall and the com-
pletion of the recovery may not exceed
approximately 20 degrees.
(c) For turning flight stalls, the ac-
tion of the airplane after the stall may
not be so violent or extreme as to
make it difficult, with normal piloting
skill, to effect a prompt recovery and
to regain control of the airplane. The
maximum bank angle that occurs dur-
ing the recovery may not exceed—
(1) Approximately 60 degrees in the
original direction of the turn, or 30 de-
grees in the opposite direction, for de-
celeration rates up to 1 knot per sec-
ond; and
(2) Approximately 90 degrees in the
original direction of the turn, or 60 de-
grees in the opposite direction, for de-
celeration rates in excess of 1 knot per
second.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–84, 60 FR 30750, June 9,
1995]
§ 25.207
Stall warning.
(a) Stall warning with sufficient mar-
gin to prevent inadvertent stalling
with the flaps and landing gear in any
normal position must be clear and dis-
tinctive to the pilot in straight and
turning flight.
(b) The warning must be furnished ei-
ther through the inherent aerodynamic
qualities of the airplane or by a device
that will give clearly distinguishable
indications under expected conditions
of flight. However, a visual stall warn-
ing device that requires the attention
of the crew within the cockpit is not
acceptable by itself. If a warning de-
vice is used, it must provide a warning
in each of the airplane configurations
prescribed in paragraph (a) of this sec-
tion at the speed prescribed in para-
graphs (c) and (d) of this section. Ex-
cept for the stall warning prescribed in
paragraph (h)(3)(ii) of this section, the
stall warning for flight in icing condi-
tions must be provided by the same
means as the stall warning for flight in
non-icing conditions.
(c) When the speed is reduced at rates
not exceeding one knot per second,
stall warning must begin, in each nor-
mal configuration, at a speed, V
SW
, ex-
ceeding the speed at which the stall is
identified in accordance with § 25.201(d)
by not less than five knots or five per-
cent CAS, whichever is greater. Once
initiated, stall warning must continue
until the angle of attack is reduced to
approximately that at which stall
warning began.
(d) In addition to the requirement of
paragraph (c) of this section, when the
speed is reduced at rates not exceeding
one knot per second, in straight flight
with engines idling and at the center-
of-gravity position specified in
§ 25.103(b)(5), V
SW
, in each normal con-
figuration, must exceed V
SR
by not less
than three knots or three percent CAS,
whichever is greater.
(e) In icing conditions, the stall
warning margin in straight and turn-
ing flight must be sufficient to allow
the pilot to prevent stalling (as defined
in § 25.201(d)) when the pilot starts a re-
covery maneuver not less than three
seconds after the onset of stall warn-
ing. When demonstrating compliance
with this paragraph, the pilot must
perform the recovery maneuver in the
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