Strana 23
PPL charges.
Accelerators (42) in cooperation with specially
shaped grooves of the feeder unit (55) provide
the necessary acceleration of the breech
blocks (29,30) during pre-slide and recoil.
The breech blocks (29,30) alternately lock the
chamber during firing, insert the cartridge
into the chamber and extract the empty
cartridge. The breech block igniter, as a result
of the impact of the firing pin on the transfer
lever, pricks the mechanical primer of the
cartridge. The splined shaft (35) transmits the
rotational movement from the feeder cylinder
(33) to the feeder star (31). The feeder cylinder
(33) changes the linear movement of the feed
control (51) into the rotational movement of the
feeder star (31), which moves the cartridge belt
in the gun. The connecting lever (39) ensures
the kinematic connection between the basic
parts of the gun's automated systems. Using
the yokes (40), it connects the slides (44,45) to
each other, activates the feed mechanism and
the recoil safety (28). The slides (44,45) are
the main links of the gun's automatics. Using
the guide grooves in the cartridge belt guide
(32), the cartridge belt is correctly and safely
fed into the gun. The rear retractors (52,53)
simultaneously with the front retractors (11,12)
push the cartridge from the cartridge belt to
the level of the barrel axis. The recoil safety
(28) prevents the inertial movement of the
moving parts of the gun in the front, extreme
position and prevents them from bouncing
when firing.
There are two possible ways of cocking the
weapon. This can be done manually, using
a special cocking lever, via a connecting lever
(for safety reasons, this is not done with live
ammunition) or electronically by pressing
a button in the cockpit, an electrical impulse
is supplied to the electric fuse of the PPL
pyrocartridge. After its initiation, the gas
pressure moves the pyrotechnic cocking
piston backwards and the piston moves the
slide, which is in the front position, backwards.
The slide, which is now in the rear position,
returns to the front position and at the same
time returns the pyrotechnic cocking piston
to its original position. Aircraft that have the
GSh-23 (GSh-23L) as part of their integral
armament have the option of re-cocking
twice in the event of a malfunction (delay)
and thus remove the failed cartridge from
the weapon's automatic process and insert
a new cartridge into the cartridge chamber.
The UPK-23-250 suspended container does
not have this capability, due to a different
electrical installation, because it has only
one PPL pyro cartridge connected to the
firing circuit out of a total of three pieces (the
remaining two only act as ballast and seal the
pyro cartridge space).
These serve as gas pressure sources (up
to 255MPa), which are created by a burning
powder charge for cocking the breech of the
weapon, or for removing a failed cartridge.
Three pieces are stored in a special cassette,
which is placed on the gas coupling. It consists
of its own brass cartridge, a powder charge
of nitrocellulose seven-hole powder, an EKV
electric primer, pressed into the primer bed
in the bottom of the cartridge and a sealing
plug. The sealing plug in the blind part of the
cartridge is dark purple.
After pressing the trigger on the pilot's control
column, an electrical impulse is supplied from
the aircraft's onboard network to the trigger
electromagnet and the armature is pulled
in. This movement is transferred to the main
trigger bar, which subsequently releases the
firing pin. The firing pin, by means of a spring,
strikes the primer of the cartridge, and a round
is expended. As soon as the round passes the
gas discharge holes in the barrel, the gases
pass through them and the gas coupling and
simultaneously into the gas cylinder space in
front of the piston, which is located with the
slide in the far forward position, and into the
space of the second cylinder behind the piston,
located with the slide in the far rear position.
This sets the automatically moving parts of
the weapon in motion. Parts from the forward
position create recoil and parts from the rear
position perform pre-slide functions. The slide,
which moves with the gas piston towards the
rear, performs the following actions: the
front slide with the bolt is moved down, thus
unlocking the cartridge chamber, the front
slide cocks the firing pin, which is caught by
the auxiliary trigger tooth. After unlocking,
the bolt the cartridge is extracted. Halfway
through the bolt stroke, the cartridge is
ejected from the bolt via the ejector. After the
cartridge is ejected, the bolt moves the ejector
to the other side. When the slide is retracted,
the front and rear slide eject the cartridge
from the ammunition belt and insert it into
the bolt jaws. At the same time, as one slide
is retracted, the other slide is simultaneously
advanced. Then, when the slide is advanced,
the front slide is raised, the auxiliary trigger
tooth is engaged, and the round is inserted
into the chamber and is locked in place. At the
Cocking of the Weapon
PPL Charges
Gun Function During Firing
INFO Eduard
23
October 2025
TECHNICS / EQUIPMENT