GAU-12, 25mm Gun Flashcards
Characteristics of the GAU-12 25mm Gun
Percussing Fired, 5-Barrel Gatling gun, gun station #1 on the U model gunship
Utilizes the worlds _______ linear linkless feed system
largest
How many rounds can the feed system store?
3000 rounds
How is the GAU-12 powered?
The aircraft utility hydraulic system
What is the purpose of the GAU-12?
To provide a barrage of fire for personnel suppression/incapacitation and against light material targets.
What is the fire rate?
1800 +/- 100 RPM
Selectable burst lengths of. . .
15, 25, 50, 100, 350
How many rounds can be fired unrestricted?
450 rounds
Capable of continuous use by. . .
following a restricted firing schedule
A __ minute cool down returns the gun to the unrestricted firing schedule
20
How many major components?
7
What are the major components?
- Gun Housing
- Gun Barrels
- Breech Bolt Assembly
- Firing/Safing Cam
- Locking/Unlocking Cam
- Transfer Unit
- Gun Drive Gearbox
Supports aft end gun support, provides mounting surfaces other components, houses the forward rotor, track assembly, and rear cover.
Gun Housing
Attached to forward rotor by interrupted locking lugs.
Gun Barrels
Performs 7 functions of feeding, chambering, locking, firing, unlocking, extracting, and positioning live rounds/spent casings in the gun transfer unit.
Breech Bolt Assembly
Allows for safing or firing of gun. When actuated, the solenoid moves the firing lever, which moves the safing cam, allowing the cocking pin to fall off the firing cam path, releasing the firing pin to strike the primer. With the safing pin installed, the safing cam will not open, mechanically safing the gun.
Firing/Safing Cam
Provides a means to lock the bolt into the forward rotor for firing, preventing the breech bolt from recoiling after firing, and unlocking after firing allowing the spent case to be extracted. The locking roller on the breech bolt follows the cam path.
Locking/Unlocking Cam
Attached directly to the gun and is driven by the forward rotor. Feeds round into the gun and returns spent cases from the gun to ASHS.
Transfer Unit
Attached to the rear of the gun and provides mechanical power from the flexible driveshaft for gun rotation. Incorporates a manual drive handle to rotate the gun.
Gun Drive Gearbox
Bolted together and provides a mounting surface for the tracks that guide the breech bolt assemblies
Forward rotor and Track Assembly
Provides the bearing surface that supports the barrel cluster.
Mid Barrel support
Located within the mid barrel support. Prevents barrels from rotating and unlocking.
Barrel clamp
Prevents barrels from spreading out due to centrifugal force caused by gun rotation.
Muzzle clamp
Houses components of bolt assembly and rides in the tracks.
Bolt carrier
Follows the elliptical cam path, allowing the bolt to travel forward and aft, transporting the rounds through firing cycle.
Bolt roller
Incorporates a locking roller
Cam follower
Contacts the locking/unlocking cam to rotate breech bolt, locking it into the firing position.
Locking roller
Connected to firing pin and rides along the firing/safing cam controlling the movement of the firing pin.
Cocking pin
ASHS
Ammunition Storage Handling System
The ASHS provides storage for. . .
ammunition and spent cases
The ASHS provides for ___ ________ and supplies __________ to the gun
gun rotation
ammunition
The ASHS magazine is a. . .
linear linkless feed system
The ASHS magazine consists of. . .
two 1500 round bays moving at half gun speed.
Mounted directly on the backside of the magazine, it is hydraulically driven from the aircraft utility hydraulic system.
ASHS gearbox
The ASHS gearbox directly drives the. . .
ASHS
The ASHS gearbox drives the gun via the ________ __________ attached to the ___ _____ _______.
flexible driveshaft
gun drive gearbox
Moves ammunition within the magazine
Chain ladder
Alternately feeds live rounds from each bay, accelerates them, and passes them to the flexible conveyor for transport. Decelerates spent cases to ASHS speed and separates them back into the individual bays.
Magazine Transfer Unit
Passes the rounds between the gun transfer unit and the magazine transfer unit. Consists of 2 sections of flexible chute with hard section incorporating the Shell Extraction System(SES)
Conveyor Assembly
Mounted in the conveyor assembly between gun and magazine. Contains the extractor gate. Extracts 7 spent cases from the end of each burst to prevent spent cases from being chambered into the gun during clearing cycle.
Shell Extraction System(SES)
Mounted on the top of the magazine and is attached to the SES. During the clearing cycle, spent cases are ejected from the chute and into the spent case tray by the extractor gate.
Spent Case Tray
The TRAY Full light illuminates at . . .
200 spent casings
The Spent Case Tray’s inhibits firing(reaches maximum capacity) at
250 spent casings
Used by ground maintenance to manually load and unload ammunition.
Loader/Downloader
The SES and gun incorporate sensors used to detect the speed and direction of gun rotation, used for firing and clearing.
Electrical Sensors
Prevents hazardous buildup of explosive gases generated by firing the gun. Consists of a hood and Kevlar curtain which surrounds the gun and part of the ASHS.
Gun Gas Purge System
What doubles as a fragment container shield in the event of catastrophic gun failure?
The hood and Kevlar curtain of the Gun Gas Purge System
