If certification for ski operation is requested, the rotorcraft, with
skis, must be designed to withstand the following loading conditions
(where *P* is the maximum static weight on each ski with the
rotorcraft at design maximum weight, and *n* is the limit load factor
determined under §29.473(b)):

(a) Up-load conditions in which --

(1) A vertical load of *Pn* and a horizontal load of *Pn/4*
are simultaneously applied at the pedestal bearings; and

(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.