Crew Served Weapons

Question 1

GAU-21 Characteristics

Answer 1

.50 Caliber 950-1100 Rounds/minute Air-cooled, short recoil operated, fires from open bolt position.

Question 2

The GAU-21/M290D is not authorized to be installed in the following configurations:

Answer 2

• With RHEP and RIB Aux fuel tank installed
• With a torp on the RHEP

Question 3

M240D Characteristics

Answer 3

• Air Cooled, Gas-operated
• fires from open bolt position
• 7.62mm round
• Rate of Fire: 650-950 (Gas Plug dependent)
• 3 Gas Plug settings

Question 4

Ammunition Types

Answer 4

1. Ball
2. Tracer
3. Dim Tracer
4. Armor Piercing
5. Armor Piercing Incendiary
6. Armor Piercing Incendiary-Tracer
7. Armor Piercing Explosive Incendiary
8. Blank
9. Dummy

Question 5

Ball Ammo

Answer 5

• Used in rifles, pistols, machine guns, SMG, etc against personnel and unarmored targets.
• Normally a lead slug with soft steel core
• Markings: None

Question 6

Tracer Ammo

Answer 6

• Allows gunner to see line of fire.
• Flame generated at the aft end of the round
• Markings:
  
  • .50 Cal: Brown Tip
  • 7.62mm: Orange Tip

Question 7

Dim-Tracer Ammo

Answer 7

• Gunner sees line of fire on NVGs (invisible to naked eye)
• Markings:
  
  • .50 Cal: Lavender Tip
  • 7.62mm: Green Tip/White Ring OR Pink Tip/Purple Ring

Question 8

Armor Piercing

Answer 8

• Used in machine guns against bullet resistant targets.
• Jacket and core of hardened steel alloy
• Markings:
  
  • .50 Cal and 7.62mm: Black Tip

Question 9

Armor Piercing Incendiary

Answer 9

• Bullent has the configuration of armor piercing
• Mixture inside ignites upon impact
• Markings:
  
  • .50 Cal: Silver Tip
  • 7.62mm: N/A

Question 10

Armor Piercing Incendiary-Tracer

Answer 10

• Same as API (Armor Piercing Incendiary) with tracer
• Markings:
  
  • .50 Cal: Red/Orange Tip, Silver Ring
  • 7.62mm: N/A

Question 11

Armor Piercing Explosive Incendiary

Answer 11

• Contains a mixture of zirconium, I-36, and Composition A-4
• Provides penetration, fragmentation, and fire starting
• Markings:
  
  • .50 Cal: Green Tip, Grey Ring

Question 12

Blank

Answer 12

• Absence of bullent identifies a Blank
• Dangerous to fire a blank at personnel at distances less than 20 yds
• Markings:
  
  • .50 Cal: N/A
  • 7.62mm: No Bullet

Question 13

Dummy

Answer 13

Consists of:

• Casing and Ball Bullet
• 2 drilled holes in the case
• Training for loading, unloading, and firing weapon (inert)

Question 14

M240D Ranges

Answer 14

• Maximum Range: 3,725m
• Max Effective Range: 1,200m
• Tracer Burnout: 900m

Question 15

GAU-21 Ranges

Answer 15

• Maximum Range: 6,500m
• Max Effective Range: 1,850m
• Tracer Burnout: 1,110m

Question 16

Gas Plug Settings for M240D

Answer 16

• Setting 1 is used for normal operations
• Settings 2 and 3 used when:
  
  • There’s Carbon Build-up
  • Cold Wx
  • Dusty conditions
• Exceeding 650 Rounds/min in settings 2 and 3 when conditions do not warrant may result in cracked bolt guide rails.

Question 17

GAU-21 Fields of Fire

Answer 17

Question 18

M240D Fields of Fire

Answer 18

Question 19

Cycle of Operations

Answer 19

1. Feeding
2. Chambering
3. Locking
4. Firing
5. Unlocking
6. Extracting
7. Ejecting
8. Cocking

Question 20

Weapons Free

Answer 20

Fire only at targets not positively identified as FRIENDLY IAW current ROE and SPINS.

Question 21

Weapons Tight

Answer 21

Fire only at targets positively identified as HOSTILE IAW current ROE and SPINS.

Question 22

Weapons Hold

Answer 22

Fire only in self-defense or in response to a formal order.

Question 23

METT-TC

Answer 23

1. Mission
2. Enemy
3. Terrain
4. Troops
5. Time
6. Civilians

Question 24

Trajectory Shift

Answer 24

When the boreline axis of the weapons differs from the flight path of the aircraft, the forward velocity of the aircraft causes a change in the direction and velocity of the projectile.

Question 25

Projectile Jump

Answer 25

When a projectile’s elevation is altered by the slip stream.