to their designed shape within 30 seconds;
however, depending on ambient temperature, they
may require additional air pressure. Air pressure
can be added by unscrewing the locking device,
pushing in on the valve, and blowing air into the
preserver through the oral inflation tube. The
LPU-23A/P or the LPU 24A/P life preserver
assemblies have an automatic inflation device
designated the FLU-8A/P.
The FLU-8A/P automatic inflation assembly
c o n s i s t s o f a b o d y a s s e m b l y a n d a s e n s or
housing. The body assembly contains a cartridge,
piercing pin, spent-cartridge indicator, firing
check port, packing loop, cam lever, lanyard
assembly, and nylon release pin. The body
assembly also provides for the attachment of a
c h a r g e d C O2 c y l i n d e r . T h e s e n s o r h o u s i ng
contains an electronic circuit, two batteries, and
a sensor plug assembly containing the battery
contact spring and the sensor pin. The inflation
devices are attached to each valve stem located
on the waist lobes. In addition, a beaded handle
with a manual inflation lanyard is connected to
each inflation device.
N O T E : T h e F L U - 8 A / P c a n b e o p e r a t ed
either manually or automatically, although the
manual mode is considered the primary mode.
MANUAL MODE. The attached lanyard
assembly, when pulled, rotates the cam lever,
releasing the packaging loop lanyard from the
nylon release pin and forcing the piercing pin
into the diaphragm of the CO2 cylinder. The CO2,
under pressure, is forced through the body of the
device to inflate the life preserver.
AUTOMATIC OPERATION. The second-
ary operating mode is automatic. Upon immer-
sion in freshwater or salt water, a conducting path
is established between the sensor pin and the case,
completing the electrical circuit. A resistance
network requires the conductivity of the water to
be at an established minimum. If the con-
ductivity is present, two series-connected, dry-
storage batteries energize the electronic circuit,
which then discharges to fire the cartridge.
B a l l i s t i c e n e r g y , p r o d u c e d b y t h e b u r n i ng
cartridge, forces the spent-cartridge indicator pin
into the firing check port and propels the
piercing pin into the diaphragm of the CO2
cylinder. As the piercing pin moves forward, the
packaging loop lanyard is released from the body
of the inflator. The CO2, under pressure, is forced
t h r o u g h t h e b o d y o f t h e d e v i c e t o i n f l a t e
the life preserver.
N O T E : T h e F L U - 8 A / P i s a n e m e r g e n cy
backup system. Always, if possible, manually
inflate the LPU prior to water entry.
T h e s e l i f e p r e s e r v e r s p r o v i d e b u o y a n cy
that ranges from 29 to 65 pounds. This may
pointed out that this is the minimum buoyancy
the preserver provides and that the natural
b u o y a n c y o f t h e b o d y p r o v i d e s a d d i t i o n al
Figure 5-3.Aircrewman grasping shoulder straps.