The pilots and copilots internal initiator
handles transfer a detonation wave signal to the
connecting SMDC assemblies, which are routed
throughout the cockpit area. In turn, the SMDC
assemblies initiate four detonating cord
assemblies, which are mounted on the periphery
of the two canopies and the two hatches. The
detonating cord assemblies sever or fracture the
stretched acrylic canopies and hatches. FLSC
assemblies, which are simultaneously initiated,
sever the two wing fillet supports and the two
upper wing-to-fuselage fillets, which extend into
the TACCO and SENSO hatch area.
Actuation of the TACCO or SENSO internal
SMDC initiator will sever only the hatch, the
upper wing-to-fuselage -fillet, and the wing fillet
support at the crew station in which the initiator
was activated. Explosive one-way transfers located
forward of the TACCO and SENSO crew stations
prevent the detonation wave from severing the
pilot and copilot canopies.
It is virtually impossible to initiate the system
at any point other than an initiator handle. As
compared to hot-gas systems, this system maybe
considered immune to ordinary shop hazards. The
system is self-sufficient and independent. It
depends upon no other system for aid or
assistance, and it does not contribute aid,
assistance, or sequence to any other aircraft
system. The S-3A system is much less susceptible
to inadvertent actuation than hot-gas systems, and
hence more convenient and safe for maintenance
personnel.
CARTRIDGES AND CARTRIDGE-
ACTUATED DEVICES (CAD)
Learning Objective: Recognize the service
life and expiration dates of cartridges and
cartridge-activated devices.
The types of explosive devices incorporated
in egress systems are varied. The AME working
with these devices must know how they function,
their characteristics, how to identify them, their
service-life limitations, and all safety precautions.
The AME who understands the importance of
all of these factors and who correctly uses the
maintenance manuals is better equipped to super-
vise and train others. The following manuals are
required for the AME to meet the above
requirements:
1.
2.
3.
4.
5.
Description, Preparation for Use, and
Handling Instructions, Aircrew Escape
Propulsion System (AEPS) Devices, NAV-
AIR 11-85-1
General Use Cartridges and Cartridge
Actuated Devices for Aircraft and
Associated Equipment (CADS), NAV-
AIR 11-100-1.1, NAVAIR 11-100-1.2, and
NAVAIR 11-100-1.3
Specific aircraft MIMs
OP 4, Ammunition Afloat
OP 5, Ammunition and Explosives Ashore
SERVICE LIFE
The service life of a CAD is the specific period
of time that it is allowed to be used. These periods
of time are affected by various environmental
conditions, which have resulted in the assignment
of time limits or overage requirements. These
limits are shelf life and installed life.
The establishment of service-life limits is based
upon design verification tests, qualification tests,
and surveillance evaluations. The established
limits are approved by the Naval Air Systems
Command. Therefore, the establishment of
service-life time limits is not arbitrary and must
be adhered to as specified.
Prior to deployment to areas that do not
permit ready supply and servicing of cartridges
or cartridge-actuated devices, an inspection must
be made of all CADs service-life expiration dates.
If, during this inspection, it is determined that a
CAD will become overage during the period of
the deployment, the CAD must be replaced prior
to the deployment. Before installation of any
CAD, the service-life expiration date of the unit
must be checked to ensure that the unit is not
overage and will not become overage prior to the
next periodic maintenance cycle of the aircraft.
During standard depot level maintenance
(SDLM), the expiration dates of all installed
CADs must be checked. Those CADs assigned to
organizational level for maintenance and that have
expiration dates prior to the next scheduled
inspection after the aircraft is returned to its
custodian must be replaced. CADs assigned to
depot level for maintenance that have expiration
dates falling prior to the next scheduled SDLM
should also be replaced. The exception is systems
replaced exclusively through the use of a field
modification team. Adherence to these procedures
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