(c)
For commuter category airplanes, each seat and the supporting structure must be designedfor occupants weighing atleast170pounds when subjected totheinertia loadsresultingfromtheultimate staticloadfactorsprescribedinSec.23.561(b)(2) of this part. Each occupant must be protected from serious head injury when sub-jected to the inertia loads resulting from these load factors by a safety belt and shoulder harness, with a metal-to-metal latching device, for the front seats; and a safety belt, or a safety belt and shoulder harness, with a metal-to metal latching device, for each seat other than the front seats.]

(d)
Each restraint system must have a single-point release for occupant evacuation.

(e)
The restraint system for each crewmember must allow the crewmember, when sea-ted with the safety belt and shoulder harness fastened, to perform all functions necessary for .ight operations.

(f)
Each pilot seat must be designed for the reactions resulting from the application of pilot forces to the primary .ight controls as prescribed in Sec. 23.395 of this part.

(g)
There must be a means to secure each safety belt and shoulder harness, when not in use, to prevent interference with the operation of the airplane and with rapid occupant egress in an emergency.

(h)
Unless otherwise placarded, each seat in a utility and acrobatic category airplane must be designed to accommodate an occupant wearing a parachute.

(i)
The cabin area surrounding each seat, including the structure, interior walls, ins-trument panel, control wheel, pedals, and seats within striking distance of the occupant’shead or torso(with the restraint systemfastened) mustbefree ofpo-tentiallyinjurious objects, sharp edges,protuberances, and hard surfaces.If energy absorbing designs or devices are used to meet this requirement, they must protect the occupant from serious injury when the occupant is subjected to the inertia loadsresultingfromtheultimate staticloadfactorsprescribedinSec.23.561(b)(2) of this part, or they must comply with the occupant protection provisions of Sec.

23.562 ofthispart, as requiredinparagraphs(b) and(c) of this section.

(j)
Each seat track must be .tted with stops to prevent the seat from sliding o. the track.

(k)
Each seat/restraint system may use design features, such as crushing or separation of certain components, to reduce occupant loads when showing compliance with the requirements ofSec. 23.562ofthispart; otherwise,the system must remain intact.

(l)
Forthepurposesof thissection,afront seatisaseatlocated ata .ightcrewmember station or any seat located alongside such a seat.

(m)
Eachberth, orprovisionsfor alitter,installedparallelto thelongitudinalaxis ofthe airplane, mustbedesigned so that theforwardparthas apadded end-board, canvas diaphragm, or equivalent means that can withstand the load reactions from a 215 pound occupant when subjected to the inertia loads resulting from the ultimate staticloadfactors ofSec.23.561(b)(2) of thispart.In addition–

(1)
Eachberth orlitter musthave an occupant restraint system and may nothave corners or other parts likely to cause serious injury to a person occupying it during emergency landing conditions; and

(2)
Occupant restraint system attachments for the berth or litter must withstand the inertia loads resulting from the ultimate static load factors of Sec. 23.561 (b)(2)of this part.

(n)
Proof of compliance with the static strength requirements of this section for seats andberths approved aspartof thetypedesignandforseat andberthinstallations may be shown by–

(1)
Structural analysis, if the structure conforms to conventional airplane types for which existing methods of analysis are known to be reliable;

(2)
A combination of structural analysis and static load tests to limit load; or