Sec. 25.499 - Nose-wheel yaw and steering.
(a) A vertical load factor of 1.0 at the
airplane center of gravity, and a side component at the nose wheel ground
contact equal to 0.8 of the vertical ground reaction at that point are
(b) With the airplane assumed to be in
static equilibrium with the loads resulting from the use of brakes on one
side of the main landing gear, the nose gear, its attaching structure, and
the fuselage structure forward of the center of gravity must be designed
for the following loads:
(1) A vertical load factor at the center
of gravity of 1.0.
(2) A forward acting load at the
airplane center of gravity of 0.8 times the vertical load on one main
(3) Side and vertical loads at the
ground contact point on the nose gear that are required for static
(4) A side load factor at the airplane
center of gravity of zero.
(c) If the loads prescribed in paragraph
(b) of this section result in a nose gear side load higher than 0.8 times
the vertical nose gear load, the design nose gear side load may be limited
to 0.8 times the vertical load, with unbalanced yawing moments assumed to
be resisted by airplane inertia forces.
(d) For other than the nose gear, its
attaching structure, and the forward fuselage structure, the loading
conditions are those prescribed in paragraph (b) of this section, except
(1) A lower drag reaction may be used if
an effective drag force of 0.8 times the vertical reaction cannot be
reached under any likely loading condition; and
(2) The forward acting load at the
center of gravity need not exceed the maximum drag reaction on one main
gear, determined in accordance with §25.493(b).
(e) With the airplane at design ramp
weight, and the nose gear in any steerable position, the combined
application of full normal steering torque and vertical force equal to
1.33 times the maximum static reaction on the nose gear must be considered
in designing the nose gear, its attaching structure, and the forward
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25-23, 35 FR 5673, Apr. 8, 1970; Amdt. 25-46, 43 FR
50595, Oct. 30, 1978; Amdt. 25-91, 62 FR 40705, July 29, 1997]