Section 25.233

14 CFR Ch. I (1-1-19 Edition)

for takeoff, taxiing, and landing, must
be established.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25-108, 67 FR 70828, Nov.
26, 2002]

Section 25.233 Directional stability and control.
(a) There may be no uncontrollable
ground-looping tendency in 90Section cross
winds, up to a wind velocity of 20 knots
or 0.2 VSR0, whichever is greater, except
that the wind velocity need not exceed
25 knots at any speed at which the airplane may be expected to be operated
on the ground. This may be shown
while establishing the 90Section cross component of wind velocity required by
Section 25.237.
(b) Landplanes must be satisfactorily
controllable, without exceptional piloting skill or alertness, in power-off landings at normal landing speed, without
using brakes or engine power to maintain a straight path. This may be
shown during power-off landings made
in conjunction with other tests.
(c) The airplane must have adequate
directional control during taxiing. This
may be shown during taxiing prior to
takeoffs made in conjunction with
other tests.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25-23, 35 FR 5671, Apr. 8,
1970; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978;
Amdt. 25-94, 63 FR 8848, Feb. 23, 1998; Amdt.
25-108, 67 FR 70828, Nov. 26, 2002]

Section 25.235

Taxiing condition.

The shock absorbing mechanism may
not damage the structure of the airplane when the airplane is taxied on
the roughest ground that may reasonably be expected in normal operation.

spaschal on DSK3GDR082PROD with CFR

Section 25.237

Wind velocities.

(a) For land planes and amphibians,
the following applies:
(1) A 90-degree cross component of
wind velocity, demonstrated to be safe
for takeoff and landing, must be established for dry runways and must be at
least 20 knots or 0.2 VSR0, whichever is
greater, except that it need not exceed
25 knots.
(2) The crosswind component for
takeoff established without ice accretions is valid in icing conditions.

(3) The landing crosswind component
must be established for:
(i) Non-icing conditions, and
(ii) Icing conditions with the most
critical of the landing ice accretion(s)
defined in Appendices C and O of this
part, as applicable, in accordance with
Section 25.21(g).
(b) For seaplanes and amphibians,
the following applies:
(1) A 90-degree cross component of
wind velocity, up to which takeoff and
landing is safe under all water conditions that may reasonably be expected
in normal operation, must be established and must be at least 20 knots or
0.2 VSR0, whichever is greater, except
that it need not exceed 25 knots.
(2) A wind velocity, for which taxiing
is safe in any direction under all water
conditions that may reasonably be expected in normal operation, must be established and must be at least 20 knots
or 0.2 VSR0, whichever is greater, except
that it need not exceed 25 knots.
[Amdt. 25-42, 43 FR 2322, Jan. 16, 1978, as
amended by Amdt. 25-108, 67 FR 70827, Nov.
26, 2002; Amdt. 25-121, 72 FR 44668, Aug. 8,
2007; Amdt. 25-140, 79 FR 65525, Nov. 4, 2014]

Section 25.239 Spray characteristics, control,
and stability on water.
(a) For seaplanes and amphibians,
during takeoff, taxiing, and landing,
and in the conditions set forth in paragraph (b) of this section, there may be
no - 
(1) Spray characteristics that would
impair the pilot-s view, cause damage,
or result in the taking in of an undue
quantity of water;
(2)
Dangerously
uncontrollable
porpoising, bounding, or swinging tendency; or
(3) Immersion of auxiliary floats or
sponsons, wing tips, propeller blades,
or other parts not designed to withstand the resulting water loads.
(b) Compliance with the requirements of paragraph (a) of this section
must be shown - 
(1) In water conditions, from smooth
to the most adverse condition established in accordance with Section 25.231;
(2) In wind and cross-wind velocities,
water currents, and associated waves
and swells that may reasonably be expected in operation on water;

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