Ballistic Munitions Flashcards
Rocket spin rate
9-10 revolutions per second.
PBXN stands for?
Polymer Bonded Explosive Navy
LX stands for?
Livermore Explosive
Impoved firestarting capability in PGU series provided by?
Zirconium Pellet
Tracer Material in TP-T rounds?
Magnesium-Teflon-Vitron
Fixed Gun Reticle
Calibrated for 200ft, 100kt level delivery and adjusts for laser. Reticle is 40mils wide and each notch is 5 mils.
Time delay in SAPHEI?
300 milliseconds
20mm dispersion
7.5 mil dispersion (7.5m at 1KM)
APKWS
1) employment range
2) Optiumum employment
3) Total Climb
1) 1,500m-5,000m
2) 3,000m-4,000m
3) 1,000’ at max range shot
APKWS TOF
1,500m -> 4 sec TOF 3.5 sec total lase 2,000m -> 5 sec TOF 3.5 sec total lase 3,000m -> 8 sec TOF 5 sec total lase 4,000m -> 12 sec TOF 7 sec total lase 5,000m -> 18 sec TOF 11 sec total lase
Rocket Reticle
Calibrated for 100’ level delivery auto adjusts for changing airspeed. Floats for 15 sec with laser. Reticle is 40 mils wide and each notch is 5 mils spacing.
APKWS ROT
1) Outside of 2,500m, below 500ft, or hovering use 3 deg.
2) Inside of 2,500m and above 1,200ft use 1 deg.
4 Principles of accurate employment
1) Always keep sight of the target
2) Low energy entry: 40-45 kts, 40-45% Q
3) Release inside parameters
4) Pulloff -> Nose-Power-Pull
Low Alt Pop
120kt ingress < 300’ AGL, 1.6-1.2 pop, 1.0 tip-in. Pop with power.
Medium Alt Delivery
100Kt ingress, 1,500’ AGL, 1.8-1.6 Level Speed Change 1.2 to 1.0 tip-in
Mk 149 Mod 0 Dispersion Pattern
10 deg: 35m x 200m
20 deg: 35m x 100m
30 deg: 35m x 70m
Components of APKWS guidance section
1) Battery
2) Inertial Measurement Unit
3) Guidance Computer
4) Seeker Optics
5) Seeker Electronics
6) Control Actuation System
20mm Danger Close
300m -> 60m
800m -> 80m
1,500m -> 115m
2.75” HE Danger Close
300m -> 140m
800m -> 210m
1,500m -> 305m
2.75” Flechette Danger Close
1,000m -> 170m
APKWS Danger Close
95m
Motor Required for APKWS II
Mk 66 Mod 4
APKWS Guidance Section Limit
750 Cumulative Captive Carriage Hours
Rocket Pod Required for APKWS II
LAU-61 E/A
LAU-68 F/A
Boresight 5 deg above armament datum line
APKWS Key Launch Events and Timing
-Battery Power Up 0.3 sec after launch, Completion of power up 0.4sec wings deploy. IMU and processor initialization 0.70 sec after launch. Sensors look to acquire reflected laser energy 0.85 sec and will direct wing to perform de-roll maneuvers until motor burnout (1.1 sec).
If laser energy not detected what will APKWS do?
Enter Attitude Hold.
APKWS is how much longer/heavier?
9.8# heavier, 18.5” longer
M50 Series Ammo Types
1) M55A2 (TP) - Blue with white writing
2) M220 (TP-T) - Blue with white writing orange T
3) M56A3 (HEI) - Yellow, red band, black writing
4) M242 (HEI-T) - Yellow, red band, black writing, orange T.
M50 Series
1) Muzzle Velocity
2) Tracer Visibility
3) Arming Distance/Fuze
1) Muzzle Velocity: 3,380 +/- 50 @ 78ft
2) 1,170m visibility
3) 20-35 ft
PGU Series
1) Muzzle Velocity
2) Tracer Visibility
1) Muzzle Velocity: 3,410 fps
2) 3.2 sec or 1,800-2,200m
PGU Series Types
1) PGU-27 (TP) - Blue with white writiting
2) PGU-28 (SAPHEI) - Black, yellow, red, white writing
3) PGU-30 (TP-T) - Blue with white writing orange T
Projectile Jump
Firing RIGHT causes DOWNWARD jump. Firing LEFT causes UPWARD jump.
Trajectory Shift
Occurs when boresight axis of weapon differs from flight path of helicopter. Aim left for shots to left, aim right for shots to right. Airspeed Comp should compensate for this.
Port-Starboard Effect
When firing to the port side the effects of drift and shift are compounded because both effects are to the right. When firing to the stbd side, projectile drift cancels out trajectory shift so less compensation required.
Exterior Ballistics Factors
1) Drag
2) Yaw
3) Gyroscopic Precession
4) Projectile Drift
5) Gravity Drop
6) Wind Drift
WERM Rule
R = (W x 1000) / M
Weapons Delivery Envelope
@800m: 1500’ = 30 deg, 460’ = 10 deg
@300m: 565’ = 30 deg, 125’ = 10 deg
Where to aim for ordnance delivery?
Aim below or short. If below or short on first shots, you cause dirt and frag to fly into the enemy. They will take cover and will not be shooting back. Also, you will walk rockets through target. 90 -180 ms between shots.
LAU -61/68 Jettison Limit
130 KIAS
Jettison Delay
1) Pilot
2) Copilot/gunner
1) 700 +/- 140 milliseconds
2) 500 milliseconds
* Inboard stores jettisoned after outboard stores plus delay time to avoid collision.
Ripple Mode (LAU 61/68)
One A/C firing pulse fires all rockets with a 40 millisecond interval.
When does gun control assembly terminate the trigger command signal?
1) Single first detent trigger pull after 16 +/- 4 rounds.
2) When gun reaches azimuth or elevation limits
3) When gun position disagrees in azimuth or elevation more than 4.5 deg from the sight position command signal.
4) When pilot WING ARM FIRE button is pressed or AIM-9 switch is set to fire.
Standard Profile NTTP
Commence run-in at 1,800 to 2,000m from target at 300ft, 100-120kias. Offset 30-45 deg from final attack hdg (gunner suppresses with 20mm). At 1,000 to 1,500m commence a pop up to 1,000’ AGL gunner continues to suppress. At 700m and 500 AGL fire first rockets, observe, adjust, and fire next rockets. Pull off by 300m.
MK 436/435 MOD 0
Low impact angle point detonating fuze. Navy’s insensitive munition compliant version of M427/423 fuze. MK 436 Mod 0: 180-426m arm. Mk 435 Mod 0: 43-92m.
Mk 152 Mod 0
HE FRAG warhead. Improved Insensitive Munition Version of M151 warhead used against personnel, parked aircraft, personnel carriers, radar emplacements, trucks, small craft. 2.1 # of PBXN-110. Fuze: Mk 435 Mod 0
M151 Warhead
HE FRAG warhead. Used against personnel and soft targets (parked aircraft, personnel carriers). 2.3 # of Comp B-4. Soft steel or cast iron case. Burst Radius of 10m. Fuze: M423/M427
M229
Elongated version of M151 same tactical application designed for slow speed aircraft. HE FRAG warhead. 4.8 # of Comp B-4. Fuze: M423
M423 Fuze
Low angle impact PD fuze. Sensitive to low angle impacts as low as 5 degrees and will function on water targets. Requires sustained acceleration of 20 g’s to arm. Air travel 140-300’ and 0.63 to 0.82 sec at 27 g’s
M427 Fuze
Low angle impact PD fuze. Sensitive to low angle impacts as low as 5 degrees and will function on water targets. Requires sustained acceleration of 20 g’s to arm. Air travel 800-1250’ and 1.09 to 1.34 sec at 40 g’s
Mk 146 Mod 0
HE FRAG warhead. Navy’s insensitive munition compliant version of M229. 4.3 # of PBXN-110. Fuze: Mk 436 Mod 0 and Mk 435 Mod 0
Mk 67 Mod 1
Red Phosphorous Smoke. Contains 2.6 # of red phosphorous with improved cook off no special handling required. Buster charge of PBXN-202. Fuze: M427/Mk 352 Mod 2
Mk 352 Mod 2 Fuze
Low angle impact PD fuze. Sensitive to low angle impacts as low as 3-5 degrees and functions on water. Fuze has instantaneous impact functioning. Requires 20 g’s to arm. Air travel is 800-1200’ and 1.07 to 1.36 sec at 40 g’s
M156
White Phosphorous Smokes. Identical to Mk 67 but a soft steel case and requires special handling. 2.0 # of WP and a burster charge of Comp B-4. Fuze: M427
WDU-4A/A
Flechette. 2,205 20 grain flechettes. Fuze: M113A.
Flechettes coated in red paint. Fuze starts arming when acceleration reaches 17.5g’s and continues as long as accelerating. Assuming average of 33 g’s, fuze completely armed in 1.2 sec fuze fires when decelerates below 11 g’s. Fuze initiates 3 grams of M9 which ejects projectiles. Optimum Employment is 1,200-1,500m
Mk 149 Mod 0
Flechette. 1,179 60 grain flechettes. Fuze: M113A.
More linear beaten zone than WDU-4A/A. Optimum Employment is 900-1100m
M113A Fuze
Accel/Decel Fuze, Base fuze installed on WDU-4A/A and Mk 149 flechette warheads. Fuze requires a sustained acceleration of 33 g’s for 1.2 seconds.
M257
Overt Illum. M442 fuze functions at motor burnout. 9.0 sec delay prior to drogue chute. Total elapsed time to flare ignition is 13.5 sec. 1,000,000 candlepower for a minimum of 2 minutes illuminates 1 square mile. Descent rate is 13-15 fps
M257 Delivery
15 degrees nose up will cause the illum to travel 3,500m downrange and deploy 1,800’ above launch elevation. A 1 degree pitch change will change elevation 150 ft. A 1 degree azimuth change will shift flare 63m.
Illum Delivery Wind ROT
10 kts of wind will require a correction of 300m or heading correction of 5 degrees.
M 278
Covert Illum: M442 fuze functions at motor burnout. 700 candlepower for 180 seconds. Produces IR or Covert Illum only. .7 to 1.1 micron range.
M278 delivery
22 degrees nose up will cause the illum to travel 3,000m downrange and deploy 2,500’ above launch altitude. Motor will continue 700-1,000m.
M442 Fuze
Time fuze. Permanently installed in illum warheads. Flare candle will ignite 13.5 sec after launch. Fuze requires a sustained acceleration of 16 g’s prior to enabling and arms at motor burnout. 2,137ft/1.0 sec
LAU-130
Nearly identical to LAU-61 without thermal protective coating. Not approved for shipboard use. Smooth painted metal surface.
LAU-61
All metal reusable launcher with 2.75” rocket capacity. Mk 66 motors only. 19 position intervalometer distributes firing pulse to each launcher tube motor contact. Each launcher has a motor detent retainer that retains the rocket motor until ignition. Thermal protective coating on exterior surface and requires use of thermal barriers for thermal protection for all shipboard ops. Ground safety is provided by a safe/arming device that opens the circuit from launcher receptacle and grounds intervalometer.
LAU-68 D/A
All metal reusable launcher with capacity for 7 2.75” rocketes. Mk 66 motors only. Identical in all other respects to LAU-61 C/A
LAU-68 C/A and LAU-131 /A
Same as LAU-68 except lacks thermal protective coating and not approved for shipboard use. Smooth metal surface.
Rocket Motor (2.75”)
MOD 2: Can only be used with LAU-61 C/A and LAU-68 D/A due to HERO susceptibility. 3 wraparound fins in conjunction with fluted exhaust nozzle provide controlled spin and stabilized flight. 1,360 pounds of thrust for 1.1 seconds. Mk 125 Mod 5 igniter and tubular stabilizing rod with 5 wire hero filter. Ashore training only.
MOD 4: HERO safe and safe to hot tube load. Solid stabilizing rod and Mk 311 igniter. Set of filters in igniter and single filter under nozzle contact band.
Rockets
1) Optimum employment range
2) Flechette Optimum
1) 300-800m
2) 900-1100 for Mk 149, 1200-1500 for WDU
Factors affecting fin stabilized projectiles
1) Propellant Force
2) Center of Gravity
3) Crosswind
4) Relative Wind
Factors affecting interior ballistics
1) Tube wear
2) Muzzle Velocity
3) Trajectory
4) Propellant Burn
5) Projectile Weight
6) Tip-Off effect
7) Boresight
8) Thrust Misalignment
Rocket Components
1) Fuze
2) Warhead
3) Motor
4) Nozzle/Fin Assembly
Rocket Motor
Motor ignited by 28 Vdc power distributed by intervalometer gas pressure ruptures either the igniter case or igniter vent hole seals and ignites the propellant grain. Propellant burns from inside to outside to prevent cg shift. Salt-coated stabilizing rod prevents unstable burning of the grain. Wraparound fins are spring actuated to open and seat in the nozzle body fin slots as motor exits launcher tube. Star perforation is designed to produce a nearly constant thrust level.
Turret Designator
A/A 49-E-7 (V4)
Gun Designator
M197
Feeder Designator
M89E1
M197 Rate of Fire
650 +/- 50 rpm
Turret Range
Left/Right 110 deg
+30 deg/ -50 deg
60 deg/sec
M197 Weapon Employment Range
200-2000m
Turret Modes of Operation
1) Pilot Fixed
2) Pilot HSS
3) Gunner TSU/GUNS
4) Gunner HSS
5) Pilot Override
20MM Ammo Configurations
M50 -> Designed for high altitude air to air combat. Poor ballisitic performance at low altitudes; the inability to penetrate lightly armored ground targets and a high dud rate.
PGU -> More effective in the air to ground mission, the SAPHEI projectile is a combination of a hardened steel body and pyrotechnic fuze that allows the projectile to penetrate and detonate inside a target. Streamlined projectile reduces the projectile drag coefficient and allows better pyrotechnic ignition resulting in improved graze sensitivity and fewer duds.
2.75” WP/HE Min Safe Distance
700m
2.75” TP Min Safe Distance
500m
20MM Min Safe Distance
500m
Mk 66 Mod 4 Improvements
Mk 311 igniter, more robust case, electronic filter to counter HERO, different igniter charge, low pass threshold filter attached to igniter to counter ESD threat. Solid stabilizing rod threaded into igniter.
