Section 29.511

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

(2) A vertical load of 1.33 P is applied
at the pedestal bearings.
(b) A side load condition in which a
side load of 0.35 Pn is applied at the
pedestal bearings in a horizontal plane
perpendicular to the centerline of the
rotorcraft.
(c) A torque-load condition in which
a torque load of 1.33 P (in foot-pounds)
is applied to the ski about the vertical
axis through the centerline of the pedestal bearings.
Section 29.511 Ground load: unsymmetrical
loads on multiple-wheel units.
(a) In dual-wheel gear units, 60 percent of the total ground reaction for
the gear unit must be applied to one
wheel and 40 percent to the other.
(b) To provide for the case of one deflated tire, 60 percent of the specified
load for the gear unit must be applied
to either wheel except that the vertical
ground reaction may not be less than
the full static value.
(c) In determining the total load on a
gear unit, the transverse shift in the
load centroid, due to unsymmetrical
load distribution on the wheels, may be
neglected.

[Amdt. 29-3, 33 FR 966, Jan. 26, 196, as amended by Amdt. 27-26, 55 FR 8002, Mar. 6, 1990]

[Amdt. 29-3, 33 FR 966, Jan. 26, 1968]

WATER LOADS

spaschal on DSK3GDR082PROD with CFR

(c) Forward speed landing conditions.
The rotorcraft must contact the most
critical wave at forward velocities
from zero up to 30 knots in likely
pitch, roll, and yaw attitudes and with
a vertical descent velocity of not less
than 6.5 feet per second relative to the
mean water surface. A maximum forward velocity of less than 30 knots may
be used in design if it can be demonstrated that the forward velocity selected would not be exceeded in a normal one-engine-out landing.
(d) Auxiliary float immersion condition.
In addition to the loads from the landing conditions, the auxiliary float, and
its support and attaching structure in
the hull, must be designed for the load
developed by a fully immersed float unless it can be shown that full immersion of the float is unlikely, in which
case the highest likely float buoyancy
load must be applied that considers
loading of the float immersed to create
restoring moments compensating for
upsetting moments caused by side
wind, asymmetrical rotorcraft loading,
water wave action, and rotorcraft inertia.

Section 29.521

Section 29.519 Hull type rotorcraft: Waterbased and amphibian.
(a) General. For hull type rotorcraft,
the structure must be designed to withstand the water loading set forth in
paragraphs (b), (c), and (d) of this section considering the most severe wave
heights and profiles for which approval
is desired. The loads for the landing
conditions of paragraphs (b) and (c) of
this section must be developed and distributed along and among the hull and
auxiliary floats, if used, in a rational
and conservative manner, assuming a
rotor lift not exceeding two-thirds of
the rotorcraft weight to act throughout the landing impact.
(b) Vertical landing conditions. The
rotorcraft must initially contact the
most critical wave surface at zero forward speed in likely pitch and roll attitudes which result in critical design
loadings. The vertical descent velocity
may not be less than 6.5 feet per second
relative to the mean water surface.

Float landing conditions.

If certification for float operation
(including float amphibian operation)
is requested, the rotorcraft, with
floats, must be designed to withstand
the following loading conditions (where
the limit load factor is determined
under Section 29.473(b) or assumed to be equal
to that determined for wheel landing
gear):
(a) Up-load conditions in which - 
(1) A load is applied so that, with the
rotorcraft in the static level attitude,
the resultant water reaction passes
vertically through the center of gravity; and
(2) The vertical load prescribed in
paragraph (a)(1) of this section is applied simultaneously with an aft component of 0.25 times the vertical component
(b) A side load condition in which - 
(1) A vertical load of 0.75 times the
total vertical load specified in paragraph (a)(1) of this section is divided
equally among the floats; and

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