Figure 2-5.—Fin protector in place.
either one of the nozzles (fig. 2-3, view A) or the
fin-actuating piston (fig. 2-3, view B) to the contact disc
(fig. 2-3, views A and B) on the fin retainer. In the
Mk 66 Mod 2, both lead wires are connected directly to
the HERO filter wires which extend out of the forward
end of the stabilizing rod. When the rocket is placed in
the launcher, the contact disc is automatically in contact
with an electrical terminal that transmits the firing
impulse to the rocket.
The igniter in the 5.0-inch motor (fig. 2-4) has an
electrical lead wire post that protrudes through the
forward bulkhead closure. The electrical lead connects
the igniter to the contact band. When the rocket is
placed in the launcher, the contact band is automatically
in contact with an electrical terminal, which transmits
the firing impulse to the rocket.
Both the 2.75-inch and 5.0-inch rockets are
susceptible to radio-frequency energy when they are not
installed in the launchers.
When stowed and shipped separately from the
launcher, the Mk 4 and Mk 40 motor fins are covered
with a fin protector (fig. 2-5), which is an elongated steel
can. A conical-coiled steel spring riveted to the center
of the base inside the fin protector makes contact with
the insulated contact disc at the aft end of the fins. This
shorts out the igniter firing circuit to prevent accidental
firing of the motor.
If Mk 16 and Mk 71 motors aren’t shipped and
stowed in a launcher, they are shipped and stowed in
individual, padded, wooden crates. Fin protectors are
not used. Until actually loaded into a launcher, a metal
shielding band (fig. 2-6) is always in place over the
ignition contact band.
Figure 2-6.—Shielding band for 5.0-inch FFAR.
2-5
