alternate method used to provide operation when the
fuze is not initiated with the +300 volts dc. The
conventional mode is selected by initiating the fuze
with +300 volts dc. When the fuze is initiated with
+300 volts dc, the Mk 43 operates automatically.
The fuze circuitry produces a lobe pattern. It
radiates a pattern at right angles (fig. 1-12) to the
longitudinal axis of the weapon.
When the Mk 43 is initiated by the conventional
method, fuze functioning occurs instantaneously when
a firing pulse is received from the thermal battery. If the
alternate method is used (striker rod), the fuze is set for
either of the two functioning delays. Detonation of the
bomb is delayed by either 0.015 second or 0.100
second, depending on the delay that is selected.
FMU-140/B DISPENSER PROXIMITY FUZE
The FMU-140/B (fig. 1-13) has an optional arm
and fire (timer) mode. It is used with the Rockeye II and
Gator weapons. The FMU-140/B is a self-powered
doppler radar device acting as a radar altimeter. Arming
times and functioning altitudes are variable and are
preflight selectable on the fuze faceplate, located on the
side of the fuze. In the proximity mode, if the
preselected altitude is reached before the fuze has had
time to arm, or the dispenser is released below the
pre-selected altitude, the fuze will have the potential to
function anytime after arming. If the fuze has not
functioned by the time it reaches an altitude of 300 ±25
feet, it will function at that time.
REVIEW NUMBER 4
Q1.
All electric capability for Mk 80 with either
conical or retarding fins, thermally protected
bombs, and laser-guided bombs is provided
by _____________________.
Q2.
No unusual RADHAZ precautions are taken
when using the Mk 376 fuze because it is
classified as _____.
1-16
Figure 1-12.—Mk 43 Mod 0 target detecting device antenna
pattern.
Figure 1-13.—FMU-140/B dispenser proximity fuze.
