2.75" Rockets Flashcards
M274
Smoke Signature (Training) Fuze: M423
M151
HE “10-Pounder”
Burst 10M, Lethal 50M+
Fuze: M423, M433
M229
HE "17-Pounder" Burst 14M+, lethal 75M Fuze: M423, M433 WARNING: Due to the possibility of premature warhead detonation damaging the aircraft when firing rockets with the M229 warhead and MK66 rocket motor, a clear and obstruction free line-of-sight to the target shall exist. Minimum engagement distance is limited to 984 ft (300m) at forward velocities less than 60 KIAS, and 1480 ft (450m) at forward velocities in excess of 60 KIAS.
M156
White Phosphorus
Target marking/incendiary
Fuze: M423
M267
Multipurpose Submunition 3 M75 Practice submunitions 6 Inert submunitions WARNING: Due to possible premature expulsion of submunitions from the M261 or M267 warhead, the following restrictions apply: Firing of 2.75-inch rockets with M261/M267 warheads is limited to ranges greater than 1000 meters, and with forward airspeeds of less than 90 KIAS. If the aircraft fires while moving faster than 90 knots and the warhead prematurely functions, the aircraft can fly into/under the submunitions. A climb or a turn after firing the rocket during running/diving fire is recommended. Avoid following the rocket. • Motor blows and premature expulsion of submunitions from the M261 or M267 warhead can cause catastrophic hazard if fired over friendly troops and equipment. Firing over the heads of friendly troops and equipment is prohibited.
M261
Multipurpose Submunition 9 M73 Submunitions Fuze: M439 Can penetrate 4 inches of armor WARNING: Due to possible premature expulsion of submunitions from the M261 or M267 warhead, the following restrictions apply: Firing of 2.75-inch rockets with M261/M267 warheads is limited to ranges greater than 1000 meters, and with forward airspeeds of less than 90 KIAS. If the aircraft fires while moving faster than 90 knots and the warhead prematurely functions, the aircraft can fly into/under the submunitions. A climb or a turn after firing the rocket during running/diving fire is recommended. Avoid following the rocket. • Motor blows and premature expulsion of submunitions from the M261 or M267 warhead can cause catastrophic hazard if fired over friendly troops and equipment. Firing over the heads of friendly troopsand equipment is prohibited.
M255A1
Flechette
1,179 60 grain flechettes
35m wide cylinder of flechettes flying at mach2 fired in pairs
Fuze: M439
M259/M264
Smoke Screen White/Red Phosphorus 72 phosphorus wedges ignite at ejection WARNING:Premature expulsion of pellets from the M264 warhead can cause burning red phosphorous to fall on unprotected friendly troops and flammable equipment, causing burns and fire. firing over the heads of unprotected friendly troops and flammable equipment is prohibited. • When firing the M264 at ranges less than 5 km, reduce helicopter velocity to 90 knots or less prior to firing. This will preclude the inadvertent ingestion of red phosphorous pellets into the engine intake if a premature function/expulsion of the warhead occurs during launch.
M278
IR Illumination 250 Watts near IR 1000 candle power of visible light burns 180 sec. 4200m standoff range with M442 fuze
M257
Illumination
1 million candle power for 100 sec.or more.
3500m stand off range with integral M442 fuze.
Illuminates 1 square km at optimum height
M423
Mechanical Point Detonating Fuze
Arms at 52-110 meters
Used with M151, M156, M229, M274
M433
Resistance-capacitance multi-option time delay Super quick (open terrain) Bunker penetration (10ft) Forest Penetration (10m-45m) Used with M151, M156
M439
Resistance-Capacitance Base mounted set to expel 500m-7200m (stores for 10 days) Arming distance - 96-126m Used with M255A1, M257, M259, M261, M264, M267, M278
M442
Mechanical time delay Base mounted Set to arm at rocket motor burn-out Pyrotechnic delay 9.0 sec. Used with: M257, M278 Illumination warheads
M446
Mechanical Time Delay Base mounted Set to arm at rocket motor burn-out Phyrotechnic delay 4.5 sec Used with the M255, M269, and M264
WARNING
To minimize the probability of encountering engine surges, MK-66 rocket firing shall be limited to out-ofground- effect conditions. A two second interval shall be used for all rocket firing below 40 KIAS. The normal rocket system firing rate may be used for airspeeds above 40 KIAS. Hover firing is limited to a maximum crosswind and tailwind of 20 Knots.
WARNING
Contact arm of launcher will provide direct electrical path to motor ignition circuit if power source is accidentally applied to the contact arm when launcher is loaded/unloaded. To prevent inadvertent rocket firing, electrical tests shall not be performed with rockets in launcher, and all other possible sources of inadvertent electrical power shall be kept away from the launcher. Ensure electrical power equipment, even if turned off and unplugged, is not in the vicinity of a loaded launcher.
R IMCPU Failure default Conditions
- Fuzing will be AIRBURST 2250 meters
- Zone will be ALL.
- One firing impulse per press of the WPN-FIRE switch
R IMCPU Failure- Back up mode operation
- MASTER switch- Armed
- WEAPON SEL switch- Select rockets
- WPN-FIRE siwtch- Press to second detent.
Misfire-2.75” rocket
WARNING: Due to lack of data, structural and aerodynamic effects on the aircraft in the event of a missile/rocket hangfire are unknown.
Indication: A misfire is a rocket that has been fired but the launch motor does not ignite.
Proceed as follows:
1. Position the aircraft so that rocket is orient downrange for a period of 10 minutes.
2. Upon landing the aircraft- Notify explosive ordnance disposal.
ROCKET/MISSILE- HANGFIRE
A hangfire is an event when a rocket or missile motor
ignites and produces thrust but hangs up on/in the
launcher and does not separate from the helicopter.
The resulting missile thrust is transferred to the
helicopter and may cause control difficulty and potential
structural damage. HELLFIRE missile thrust lasts for
approximately 2.5 seconds. Control of the aircraft is
crucial during this period and recovery is dependent
upon altitude and obstacles. Failure to immediately
counter missile thrust with control inputs may cause
loss of aircraft control.
WARNING: Activation of Jettison switch during missile hangfire may cause missile launcher package to veer off course, possibly, into the aircraft or rotor disk.CAUTION: If a HELLFIRE launcher is jettisoned with a single missile on the inobard launcher rail, the launcher may contact the landing gear skid tube.
In the event of missile hangfire proceed as follows:
1. Jettison switch(es)- Activate (only in event of residual fire.)
2. LAND AS SOON AS POSSIBLE
Mod 1
Mod 1 can be inadvertently ignited by electromagnetic radiation.
Hazards of Electromagnetic Radiation to Ordnance Filters
Mod 2 & 3 have HERO
MOD 2
Is prohibited due to the possibility of ejecting the stabilizing rod
MK 66 WARNINGs
OGE conditions
2 second interval below 50 KIAS; Normal system firing rate above 40 KIAS
Maimum crosswind/tailwind of 20 knots
Do not use an MK-66 that was stored above 140’F for more than 24 hours
Discard any rocket that is dropped
Electrical tests shall not be performed with rockets in launcher, and all other possible sources of inadvertent electrical power shall be kept away from the launcher. ensure electrical power equipment is not in the vic of loaded launcher
M229 warhead w/MK66 rocket motor -10 WARNINGS
Clear and obstruction free LOS to target shall exist
Minimum engagement distance is 984 ft (450m) greater than 60 KIAS
Minimum engagement distance is 1480 ft (450m) greater than 60 KIAS
M264 warhead -10 WARNINGs
Firing over the heads of unprotected friendly troops and flammable equipment is prohibited
At ranges less than 5 km, slow to 90 knots or less prior to firing
M261/M267 warheads -10 WARNINGs
Lmiited ot ranges greater than 1000 meters
Forward airspeeds less than 90 KIAS
A climb or turn is recommended during running/diving fire (avoid following rocket)
Firing over the heads of friendly troops and equipment is prohibited
Rocket Firing Mode Selections- Two Launchers Installed
Ripple singles
Ripple pairs
Singles singles
Single Pairs
Rocket Firing Mode Selections- One Launcher installed
Ripple Singles
Single Singles
-10 CAUTION
Each launcher tube is energized sequentially regardless of load status. Placing the MASTER switch in the OFF position and returning to the ARMED position resets the rocket weapon system, and will require pressing the WPN FIRE switch for each previously fired/empty launcher tube.
-10 Note
The firing of advance precision kill weapon system (APKWS) rocket is prohibited.
A visual inspection shall be made at the conclusion of a rocket firing operation to determine the status of the remaining load.
Firing Sequence
46, 213, 75
Range to Target
Range is boxed if current laser range is being displayed. Range not boxed is last valid laser range used. Display is boxed while laser is firing and for 5 seconds after laser firing is stopped.
“L” is laser range
“P” is prepoint range
“N” is direct-to waypoint range
Rocket Status
OFF, SAFED, or ARMED
CONTACT FUZE/CUE DISTANCE key
Fuze: S, B, 10-45
CONTACT: L, N, 500-8000m
Rounded down to 250m less than 3000m
Rounded down to 500m greater than 3000m
AIRBURST FUZE/CUE DISTANCE key
L, N, 500-6000m
Rounded down to 250 m less than 3000m
Rounded down to 500m greater than 3000m
