(a) Each seat, safety belt, harness, and adjacent part of the
rotorcraft at each station designated for occupancy during takeoff and
landing must be free of potentially injurious objects, sharp edges,
protuberances, and hard surfaces and must be designed so that a person
making proper use of these facilities will not suffer serious injury in an
emergency landing as a result of the inertial factors specified in
§29.561(b) and dynamic conditions specified in §29.562.
(b) Each occupant must be protected from serious head injury by a
safety belt plus a shoulder harness that will prevent the head from
contacting any injurious object, except as provided for in §29.562(c)(5).
A shoulder harness (upper torso restraint), in combination with the safety
belt, constitutes a torso restraint system as described in TSO-C114.
(c) Each occupant's seat must have a combined safety belt and shoulder
harness with a single-point release. Each pilot's combined safety belt and
shoulder harness must allow each pilot when seated with safety belt and
shoulder harness fastened to perform all functions necessary for flight
operations. There must be a means to secure belt and harness when not in
use to prevent interference with the operation of the rotorcraft and with
rapid egress in an emergency.
(d) If seat backs do not have a firm handhold, there must be hand grips
or rails along each aisle to let the occupants steady themselves while
using the aisle in moderately rough air.
(e) Each projecting object that would injure persons seated or moving
about in the rotorcraft in normal flight must be padded.
(f) Each seat and its supporting structure must be designed for an
occupant weight of at least 170 pounds, considering the maximum load
factors, inertial forces, and reactions between the occupant, seat, and
safety belt or harness corresponding with the applicable flight and
ground-load conditions, including the emergency landing conditions of
§29.561(b). In addition --
(1) Each pilot seat must be designed for the reactions resulting from
the application of the pilot forces prescribed in §29.397; and
(2) The inertial forces prescribed in §29.561(b) must be multiplied by
a factor of 1.33 in determining the strength of the attachment of --
(i) Each seat to the structure; and
(ii) Each safety belt or harness to the seat or structure.
(g) When the safety belt and shoulder harness are combined, the rated
strength of the safety belt and shoulder harness may not be less than that
corresponding to the inertial forces specified in §29.561(b), considering
the occupant weight of at least 170 pounds, considering the dimensional
characteristics of the restraint system installation, and using a
distribution of at least a 60-percent load to the safety belt and at least
a 40-percent load to the shoulder harness. If the safety belt is capable
of being used without the shoulder harness, the inertial forces specified
must be met by the safety belt alone.
(h) When a headrest is used, the headrest and its supporting structure
must be designed to resist the inertia forces specified in §29.561, with a
1.33 fitting factor and a head weight of at least 13 pounds.
(i) Each seating device system includes the device such as the seat,
the cushions, the occupant restraint system and attachment devices.
(j) Each seating device system may use design features such as crushing
or separation of certain parts of the seat in the design to reduce
occupant loads for the emergency landing dynamic conditions of §29.562;
otherwise, the system must remain intact and must not interfere with rapid
evacuation of the rotorcraft.
(k) For purposes of this section, a litter is defined as a device
designed to carry a nonambulatory person, primarily in a recumbent
position, into and on the rotorcraft. Each berth or litter must be
designed to withstand the load reaction of an occupant weight of at least
170 pounds when the occupant is subjected to the forward inertial factors
specified in §29.561(b). A berth or litter installed within 15° or less of
the longitudinal axis of the rotorcraft must be provided with a padded
end-board, cloth diaphragm, or equivalent means that can withstand the
forward load reaction. A berth or litter oriented greater than 15° with
the longitudinal axis of the rotorcraft must be equipped with appropriate
restraints, such as straps or safety belts, to withstand the forward
reaction. In addition --
(1) The berth or litter must have a restraint system and must not have
corners or other protuberances likely to cause serious injury to a person
occupying it during emergency landing conditions; and
(2) The berth or litter attachment and the occupant restraint system
attachments to the structure must be designed to withstand the critical
loads resulting from flight and ground load conditions and from the
conditions prescribed in §29.561(b). The fitting factor required by
§29.625(d) shall be applied.