The ends of the SMDC, while in storage or
not connected in the aircraft, must be capped at
all times. Any scaring or deformation of the
transfer tip is cause for rejection. Any deformity
here will affect the direction the blast force will
travel. The tips of the SMDC act as both donor
and acceptor to receive and transfer the charge
from one SMDC segment to another. The tips
contain Hexanitrostilbene II (HSN II) while the
cord charge itself is Hexanitrostilbene I, a less
sensitive material.
CANOPY AND HATCH
EXPLOSIVE CHARGE
An explosive charge is attached to the
periphery of the pilot and copilot canopies and
the TACCO and SENSO hatches. The explosive
charge is a detonating cord, and it is applied
directly to the glass on the canopies and/or
hatches. Each detonating cord assembly is held
in place by a silicone rubber charge holder and
fiber glass retainer (fig. 2-16). The detonating cord
consists of a continuous explosive charge
contained in an O-shaped seamless lead sheath.
A threaded inlet port (transfer block) is mounted
on the fiber glass retainer to allow attachment of
the SMDC or FCDC assembly. An SMDC or
FCDC connects to the transfer block at the lower
front corner of each charge.
Actuation of an external or internal canopy
and hatch jettison initiator detonates the SMDC
or FCDC screwed into the inlet port of the
detonating cord assembly. The detonation wave
impacts and initiates the explosive booster charge,
which, in turn, initiates the detonating cord.
Initiation of the detonating cord fractures the
stretched-acrylic canopy or hatch along its
periphery. The first half of the glass is vaporized
by the heat of the flame, which slices a very
narrow and deep incision halfway through it. At
this point, the shock wave is sufficient to
fracture the remaining thickness and spatter the
glass outward.
FILLET SEVERANCE EXPLOSIVE
SHAPED CHARGE
During emergency ground egress, FLSC
assemblies sever the S-3A aircraft’s left and right
upper wing-to-fuselage fillet supports. The FLSC
cuts the attached fillet from the aircraft to allow
complete egress through the respective hatch.
The FLSC assembly is enclosed in a silicone
rubber charge holder, which is held in place by
a fiber glass retainer (fig. 2-17). The FLSC is a
continuous explosive charge contained in a
V-shaped seamless lead sheath. The silicone
rubber shaped charge holder is extremely
vulnerable to external damage because of the
softness of the material and 0.02-inch material
thickness in the area of the FLSC. A cut or tear
of the charge holder, which allows the lead
sheathed shaped charge to become exposed,
destroys the environmental seal and requires
replacement of the FLSC assembly.
Figure 2-17.—Fillet FLSC assembly.
2-21
