A line will be drawn through the service-
life expiration date shown and the new computed
expiration date entered citing the authority
for the change; for example, message num-
ber, rapid action change number, or change
number. Each new expiration date will super-
sede the previous date. The latest expiration
date entered in the aircraft logbook will
always be the final date the CAD may remain
installed in the aircraft.
When a contingency service-life extension has
been authorized for a specific CAD, the new
computed service-life expiration date (month and
year) will be added to the original aircraft logbook
entry for that CAD. When an additional service-
life extension has been granted for a specific
CAD, the new service-life expiration date (month
and year) will be added to the original aircraft
logbook entry.
CAD MAINTENANCE POLICY
Learning Objective: Identify CAD main-
tenance policy to include SMDC and
FCDC maintenance and inspection re-
quirements and safety precautions.
CAD maintenance policy prohibits un-
authorized maintenance or adjustment to a CAD
at any of the three levels of maintenance:
organizational, intermediate, or depot. Author-
ized maintenance actions are limited to removal,
inspection, and replacement unless specifically
detailed in the aircraft MIM or by a technical
directive.
CADS and items of equipment in ejection
systems are for one-time use only. They are never
to be refurbished or used again after firing. This
is equally true of functional equipment, rigid lines,
plumbing lines, and hoses. Ejection seats and
escape system components that have been used
in an ejection or fired, regardless of apparent
condition, are prohibited from reuse and must be
disposed of as directed by OPNAVINST 4790.2,
OPNAVINST 3750.6, and the applicable CAD
and rocket manual.
Because of the extreme stress and strain to the
ejection seats and escape system components
during ejection, they cannot be reused. This stress
could reduce the structural or mechanical
2-26
reliability y of these items. In the case of an
inadvertent firing of a cartridge or CAD, all
contaminated ballistic lines and devices must be
replaced because of the corrosive nature of the
explosive.
The service life of wire-braid, teflon-lined
hoses installed in ballistic applications is the same
as that of the aircraft in which it is installed, unless
it is used. A hose is considered to be used if the
device to which it is attached is fired, either
intentionally or accidentally. If this occurs, the
hose and related fittings must be replaced. Before
you install a hose or fitting (line, T, elbow, etc.),
make sure that it is not contaminated by hydraulic
fluid, oil, or a similar type of contaminant. All
hoses in the escape system must be inspected for
accidental damage at every phased inspection,
upon seat removal, after removal of any part of
the escape system, and for disconnection of any
hose.
When CADs are not installed in an aircraft,
the inlet and outlet ports must be sealed with
protective closures to prevent the entrance of
moisture and foreign matter. For shipping
purposes, the safety pins and protective closures
provided with the replacement CAD must be
returned with the replaced CAD to ensure it is in
a safe condition during handling and storage.
During ejection system maintenance actions, all
disconnected CADs and associated ballistic lines
must be protected with flexible plastic plugs that
conform to MIL-C-5501/l0A and flexible plastic
caps that conform to MIL-C-5501/l1. NAV-
AIR 11-100-1.1 provides information relating to
these caps and plugs.
SMDC AND FCDC MAINTENANCE
AND INSPECTION REQUIREMENTS
The major components of an SMDC assembly
are the stainless steel tubing (SST), outer
and inner ferrules, a silicone rubber seal,
a 0.004-inch thick SST booster cup, an explosive
booster charge, and a sheathed explosive
detonating cord. A sectioned drawing of a
standard SMDC/FCDC tip assembly is shown
in figure 2-19. The SMDC assemblies used
in the canopy and hatch severance system
are similar in design and construction except
for the length and bend configuration of
the stainless steel tubing and silver sheathed
explosive detonating cord.
