(3) Electrically
initiated
systems
have
c. Energy Transmission in Systems.
reliability comparable to gas-initiated
(1) In early aircraft escape systems, all
systems. The weight of electrical systems
propellant
actuated
devices
were
is less than gas systems since all
mechanically initiated. This mechanical
initiators, couplings, check valves, and
initiation required elaborate cable pulley
high-pressure hose can be eliminated;
arrangements to release cocked firing
however, an auxiliary power source must
pins by rotating or withdrawing sears. The
be provided.
Where the propellant
drawbacks of this system are obvious.
actuated device and the initiating device
(2) Gas-initiated systems gradually replaced
are some distance apart, no booster
these early systems. Gas systems use
initiators are needed. Electrical systems
teflon-lined, steel-braided hose and
offer the advantage of economy, smaller
stainless steel tubing to transmit the gas
size, easier installation, and less
from the gas-generating device to the
maintenance, as well as permitting
propellant actuated device to be operated.
continuity checks by pilot or ground crews.
The gas-initiated systems not only provide
The disadvantages of electrical systems
a more reliable means of initiating a
lie in their need for an external power
system of devices, but also permit the use
source and possible danger of accidental
of delay initiators and bypass thrusters to
firing caused by stray radiation, etc.
sequence operations in the system.
19
