AN/ALE-29A COUNTERMEASURES
CHAFF DISPENSING SET
The AN/ALE-29A countermeasure chaff
dispensing set, known as the chaff dispenser, is an
electronic countermeasures device. It maybe installed
in almost all Navy combat aircraft. The chaff
dispensing set includes two dispenser assemblies, two
dispenser housings, two sequencer switches, and a
programmer. The cartridge in the chaff dispenser can
eject various load configurations of Mk 46 or MJU-8/B
decoy flares and RR-129 or RR-144 chaff.
Decoy flares are used during evasive maneuvers
against heat-seeking missiles. Chaff rounds consist of
fine-shredded metal strips contained in a cylindrical
metal container. When ejected from the chaff dispenser,
the metal strips are forced from the cylindrical container
and dispersed into the atmosphere. This jams ground
controlled radar installation or radar-controlled
missiles.
Dispenser Assemblies
The dispenser assembly (fig. 10-36) contains two
major subassemblies—a glass-reinforced phenolic
plastic block and a sandwich-type primed circuit board.
The block has 30 holes so you can load the payload units.
There are four quick-release, positive-lock studs so you
can secure the block in the dispenser housing, and two
telescoping handles to make it easier to handle.
The sandwich-type printed circuit board contains
the circuitry and jacks so you can install 30 electrically
initiated Mk 131 impulse cartridges. You must also
install a connector to act as an interface between the
dispenser assembly and the dispenser housing.
You load the dispenser by putting the 30 payload
units (in plastic sleeves with plastic cartridge retainers
installed) into the block. Install an impulse cartridge in
each of the 30 jacks on the printed circuit board. Then,
attach the board to the block by two captive screws.
NOTE: Installation of the impulse cartridges
must be accomplished in a designated RF (radio
frequency) free area.
Finally, install the loaded dispenser assembly in the
dispenser housing. You need to secure it with the four
positive-lock studs of the dispenser block. The payload
units are forced from the plastic sleeves by the gas
pressure generated when the impulse cartridges are
fired. The chaff sleeve extractor, shown in figure 10-36,
is used during dispenser download procedures.
Dispenser Housings
There are two different housing configurations
available, as shown in figure 10-37. You can identify
the housings by the mounting flange configuration,
number and arrangement of mounting fasteners,
location of the sequence switch, and the cable
arrangement. These configurations are supplied so
aircraft manufacturers have flexibility in mounting
locations.
You don’t remove the housing assemblies from the
aircraft when loading. You do remove the dispenser
assembly from the housing assembly by unlocking the
four positive-lock studs. Move the dispenser assembly
to a designated area and load it. Then, return it to the
aircraft and reinstall it in the dispenser housing. Safety
switches, installed in the aircraft near the dispenser
housings, make the dispenser’s assemblies electrically
safe when the safety pin or flag assemblies are installed.
REVIEW NUMBER 5 ANSWERS TO QUESTIONS Q1. THROUGH Q5.
A1. You can load eight parachute flares in the SUU-44 flare dispenser.
A2. Eight size A sonobuoys can be launched from SUU-25F/A dispensers.
A3. The CUU-44 impulse cartridge is used to fire the SUU-25F/A impulse cartridge.
A4. The impulse cartridge is fired by 28 volts of dc.
A5. When performing organizational-level maintenance on the SUU-25F/A, you
should look for cracks or breaks in the aft retaining locks or suspension lugs,
unburned pellets or obstructors in the breech sleeve, or frayed or broken breech
leads.
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