184.108.40.206 Folding and stowage. Each seat shall be capable of being folded,
stowed and secured or unstowed quickly and easily by one man in a period not to
exceed 20 seconds multiplied by the seat size number.
3.3.5 Obstructions. Seat suspension or mounting shall not interfere with rapid
ingress or egress. Braces, legs, cables, straps and other structures shall be de-
signed to prevent snagging or tripping. Loops shall not be formed when the re-
straint system is in the unbuckled position.
3.3.6 Occupant restraint. The seats shall have an integral restraint system
with lap belt and shoulder harness for each seating position. The restraint shall
be comfortable, light in weight, and easy for the occupant to put on and remove.
Reduction in support of the occupant shall not occur due to stroking of the energy
absorbers or deformation of the seat.
220.127.116.11 Lap belt. The lap belt anchorage geometry shall be as shown on figure
4. The lap belt anchor fittings shall be attached to the stroking portion of the
seat and shall be capable of displacing plus or minus 30 degrees vertically. These
fittings shall also be capable of withstanding lateral loads when the webbing is
pulling at an angle of plus or minus 60 degrees to the normal plane of the fitting.
Lap belt retractors may be used in lieu of adjustors. In any event, lap belts
shall be prevented from falling behind or below the seat. Flexible stand-ups shall
be provided at the lap belt anchor points to project the lap belt upward and for-
ward 5 inches for each reach. Retractors or adjustors shall not be located over
hard points of the occupants skeletal structure. The force required to adjust the
webbing length shall not exceed 15 pounds and it shall be possible for the seated
occupant to easily adjust with either hand. If retractors are used, they shall not
pull with more than 15 pounds force, and shall ratchet in increments not to exceed
18.104.22.168 Shoulder straps. Seats shall be provided with shoulder straps. Either
the configuration shown in figure 5 or that shown in figure 6 shall be used. The
figure 5 configuration is preferred. Shoulder harness anchorage geometry shall
conform to figure 7. The anchorage or guide at the top of the seat shall not
permit more than 0.5 inch lateral movement of the strap at this point. Distance
between the inner edges of the shoulder straps at the seat back shall be within 3
to 5 inches. Flexible guides shall be provided on the seat back as shown on figure
7 to project the shoulder strap fittings up and forward of the seat back for easy
22.214.171.124 Inertia reel. Unless otherwise specified, provision of inertia reel or
reels shall be optional. Shoulder strap inertia reel or reels, when specified by
mission requirements (such as, a gunner's seat installation), shall pull with not
more than 3 pounds force and fully retract the shoulder strap or straps to shoulder
height in the guides described above. The reel shall be of a type which remains
locked after it locks up initially, and must be manually reset. It is preferred
that the reel be designed to lock in an identical manner to the requirements stated
in MIL-R-8236, except that the manual control handle shall not be required. After
locking, relocking of the reel shall be accomplished by turning or pushing a simple
reset device. The reel shall be located close to the shoulder strap guide point at
the back of the seat to minimize strap elongation.