Federal Aviation Administration, DOT

Section 29.497

(4) If there are two wheels forward, a
distribution of the loads applied to
those wheels under paragraphs (b)(1)
and (2) of this section in a ratio of
40:60.
(c) Pitching moments. Pitching moments are assumed to be resisted by - 
(1) In the case of the attitude in paragraph (a)(1) of this section, the forward
landing gear; and
(2) In the case of the attitude in paragraph (a)(2) of this section, the angular
inertia forces.
Section 29.481

Tail-down landing conditions.

(a) The rotorcraft is assumed to be in
the maximum nose-up attitude allowing ground clearance by each part of
the rotorcraft.
(b) In this attitude, ground loads are
assumed to act perpendicular to the
ground.
Section 29.483

One-wheel landing conditions.

For the one-wheel landing condition,
the rotorcraft is assumed to be in the
level attitude and to contact the
ground on one aft wheel. In this attitude - 
(a) The vertical load must be the
same as that obtained on that side
under Section 29.479(b)(1); and
(b) The unbalanced external loads
must be reacted by rotorcraft inertia.

spaschal on DSK3GDR082PROD with CFR

Section 29.485 Lateral drift landing conditions.
(a) The rotorcraft is assumed to be in
the level landing attitude, with - 
(1) Side loads combined with one-half
of the maximum ground reactions obtained in the level landing conditions
of Section 29.479(b)(1); and
(2) The loads obtained under paragraph (a)(1) of this section applied - 
(i) At the ground contact point; or
(ii) For full-swiveling gear, at the
center of the axle.
(b) The rotorcraft must be designed
to withstand, at ground contact - 
(1) When only the aft wheels contact
the ground, side loads of 0.8 times the
vertical reaction acting inward on one
side and 0.6 times the vertical reaction
acting outward on the other side, all
combined with the vertical loads specified in paragraph (a) of this section;
and

(2) When the wheels contact the
ground simultaneously - 
(i) For the aft wheels, the side loads
specified in paragraph (b)(1) of this section; and
(ii) For the forward wheels, a side
load of 0.8 times the vertical reaction
combined with the vertical load specified in paragraph (a) of this section.
Section 29.493

Braked roll conditions.

Under braked roll conditions with
the shock absorbers in their static positions - 
(a) The limit vertical load must be
based on a load factor of at least - 
(1) 1.33, for the attitude specified in
Section 29.479(a)(1); and
(2) 1.0, for the attitude specified in
Section 29.479(a)(2); and
(b) The structure must be designed to
withstand, at the ground contact point
of each wheel with brakes, a drag load
of at least the lesser of - 
(1) The vertical load multiplied by a
coefficient of friction of 0.8; and
(2) The maximum value based on limiting brake torque.
Section 29.497 Ground loading conditions:
landing gear with tail wheels.
(a) General. Rotorcraft with landing
gear with two wheels forward and one
wheel aft of the center of gravity must
be designed for loading conditions as
prescribed in this section.
(b) Level landing attitude with only the
forward wheels contacting the ground. In
this attitude - 
(1) The vertical loads must be applied
under SectionSection 29.471 through 29.475;
(2) The vertical load at each axle
must be combined with a drag load at
that axle of not less than 25 percent of
that vertical load; and
(3) Unbalanced pitching moments are
assumed to be resisted by angular inertia forces.
(c) Level landing attitude with all
wheels contacting the ground simultaneously. In this attitude, the rotorcraft
must be designed for landing loading
conditions as prescribed in paragraph
(b) of this section.
(d) Maximum nose-up attitude with
only the rear wheel contacting the
ground. The attitude for this condition
must be the maximum nose-up attitude

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