Be extremely careful when handling a
practice bomb loaded with a signal. Jarring
or dropping the bomb may detonate the
signal. Do not, under any circumstances,
point either end of the bomb toward another
person. Loading personnel must not place
their bodies in line with the nose or tail end
of a bomb.
1. Remove the bomb from the cardboard container.
2. Remove the cotter pin and Mk 1 firing-pin
assembly from the nose. Inspect it for rust and
deformation. Ensure the firing-pin cup is not deformed
and the firing-pin point is below the lip of its cup.
3. Inspect the blast tube for rust and obstructions.
Clean as required. When any obstructions are noted,
proceed as follows: Insert a plug gauge SK923AS503
into the center cavity. The gauge should slide into place
until the shoulder rests flush against the bomb. When
the gauge shoulder does not rest against the bomb, the
cavity is not clear. When the obstruction cannot be
removed, reject the bomb as unserviceable, and dispose
of it by following current instructions.
A signal cartridge must not be swollen or
deformed in any manner. The primer must
be flush with or slightly below the base of the
cartridge. If you attempt to install a
deformed signal, it can cause detonation.
Use extreme care when you handle a signal
cartridge. When a practice bomb is not used
after the signal has been installed, the signal
must be gently removed and replaced in the
original shipping container. The cartridge
can be reloaded and used later. Do not apply
pressure to force the signal cartridge or
firing-pin assembly into the bomb because
the assembly could become deformed and
fire the signal.
4. With the firing-pin assembly removed, elevate
the nose of the bomb. Insert the Mk 4 Mod 3 or
CXU-3A/B practice bomb signal, primer end up, into
the nose of the practice bomb. Slide it gently into place.
Do not use force. The base flange of the signal cartridge
must rest on the bore shoulder, which is about 1 1/4
inches inward from the nose of the bomb.
5. Carefully insert the firing-pin assembly with the
firing-pin end toward the signal.
6. Rotate the firing-pin assembly so that the two
notches in the lip of the forward cup line up with the
cotter pin holes in the nose end of the bomb. Do not
apply pressure to the firing pin during this procedure.
7. Insert the cotter pin through the pinholes in the
bomb body. Pass it through the notches in the firing-pin
assembly. Spread the ends of the cotter pin just enough
to retain it in place.
BDU-48 Practice Bomb
The BDU-48 practice bomb is prepared for aircraft
loading as discussed in the following steps:
NOTE: The warnings discussed for the Mk 76
Mod 5 also apply to the BDU-48.
REVIEW NUMBER 1 ANSWERS TO QUESTIONS Q1. THROUGH Q5.
For information about the GP bomb assembly you should refer to Airborne
Weapons Assembly Manual, NAVAIR 11-140-5.
A maximum of 56 square inches of thermal coating can be missing from a GP
bomb, and it is still considered thermally protected.
An M904E4 mechanical nose fuze with an M148E1 adapter booster is used with
the thermally protected Mk 80 bomb.
Only the Mk 376 and FMU-139 electrical tail fuzes are used in live GP retarded
Mk 122 arming safety switches are instilled in GP bombs in a RADHAZ-free