11C Infantry Mortar Basic Knowledge
What are the mortars primary offensive tasks?
- Establish a base of fire (along with other weapons) on which the unit can maneuver. - Destroy or neutralize enemy units. - Suppress an enemy's observation and fire. - Fix an enemy. Provide close supporting fires for the assault.
When boresighting the 81mm mortar what deflection is indexed on the M67 sight?
0000 mils deflection
The M67 sight unit must be turned in when the elevation is not within how many mils tolerance?
20 mils
What is the sustained rate of fire for a 60mm mortar?
20 rounds/min
What is the lethal radius for 60mm mortar HE?
20-28 meters for HE
What is the minimum range of the 120mm mortar ground mounted?
200 meters
What is the minimum range of the 120mm vehicle mounted?
200 meters
When using the distant aiming point method during boresight procedures, the distant aiming point should be a minimum of how many meters from the weapon system?
200 meters minimum
What is the max ord of a 60mm mortar handheld?
2300 ft AGL
When is Angle T in effect?
Angle T is in effect between 0500 and 2700 mils
What is the approximate 120mm mortar ILLUM candlepower?
Approximately 1,000,000 candlepower
On the 81mm mortar, each turn of the elevation handwheel is approximately how many mils?
Approximately 10 mils
What is the approximate 60mm mortar ILLUM candlepower?
Approximately 250,000 candlepower
What is the approximate illumination duration for 120mm ILLUM round?
Approximately 46-60 Seconds
What is the approximate illumination duration for 81mm ILLUM round?
Approximately 50-60 Seconds
What is the approximate illumination duration for 60mm ILLUM round?
Approximately 55 seconds
What is the approximate 81mm mortar ILLUM candlepower?
Approximately 600,000 candlepower
On the 81mm mortar, each turn of the traversing handwheel is approximately how many mils?
Approximately 7 mils
What is the color and markings on FRTR mortar rounds?
Blue with White Markings
How does the gunner check for mask and overhead clearance?
By sighting along the top of the cannon with his eye placed near the base plug. If the line of sight clears the mask, it is safe to fire.
What is the max rate of fire for the 81mm mortar?
30 rounds/min for 2 minutes
What is the max rate of fire for a 60mm mortar?
30 rounds/min for 4 minutes
When boresighting the 60mm and 120mm mortar what deflection is indexed on the M67 sight?
3200 mils deflection
What elevation is indexed on the M67 sight when doing boresight procedures?
3200 mils deflection and 0800 mils elevation
What is the lethal radius for the 81mm mortar?
34-38 meters
What is the maximum range of a 60mm mortar conventional?
3490 meters
At what deflection and elevation is the M67 sight stored at?
3800 mils deflection and 1100 mils elevation
What is the sustained rate of fire for the 120mm mortar?
4 rounds/min
Describe an Emergency occupation?
"Drop and shoot where you're at" An example would be 1st platoon taking contact while in a company maneuver. Mortar team will hip shoot rounds in the estimated distance and direction of the enemy position
What is the saying/phrase used for a compensated sight picture?
"Hey Diddle Diddle, Far Pole in the Middle"
What saying is used to read an M2 Compass?
"Hold black, read black. Hold silver, read silver"
What are ILLUM mortar rounds used for?
(both conventional (visible) and infrared) are used in night missions requiring illumination for assistance in observation
Why are mortar fires employed?
- Close Support Fires - Counterfires - Interdiction fires - Harassment fires - Deception fires
On the 120mm mortar, each turn of the elevation handwheel is approximately how many mils?
5 mils
On the 120mm mortar, each turn of the traversing handwheel is approximately how many mils?
5 mils
What is the max range for the 81mm mortar?
5792 meters
Ammunition must be stored how many inches off the ground?
6 Inches
How many mils are in a circle?
6400 mils
What is the max range of the 120mm vehicle mounted?
6700 meters
What is the lethal radius for the 120mm mortar?
70 meters
What is the minimum range of a 60mm mortar conventional?
70 meters
What is the max ord of a 60mm mortar conventional?
7000 ft AGL
What is the max range of the 120mm mortar ground mounted?
7200 meters
What is the minimum range of a 60mm mortar handheld?
75 meters
What is the minimum range for the 81mm mortar?
83 meters
All firing malfunctions should be considered a what?
A Misfire
What is a cookoff?
A functioning of one or more of the explosive components of a round chambered in a hot weapon, initiated by the heat of the weapon
What manual covers Tactical Employment of Mortars?
ATP 3-21.90
What is a hangfire?
Caused by a round becoming lodged in the breach preventing the rounds primer from striking the firing pin at the time of firing
What does FLOT stand for?
Forward Line Of Troops
How many sheafs are there?
Four
120mm white phosphorus rounds cannot be stored in which way?
Fuse End Down
In the defense, priority of fires is given to who?
Given first to a company or platoon that can best place effective long-range fires on the enemy
Small deflections/elevations are how many mils deflection and elevation?
Greater than 20 mils but less than 60 mils and small elevation changes are greater than 30 mils but less than 90 mils
Large deflections/elevations are how many mils deflection and elevation?
Greater than 200 mils but less than 300 mils and large elevation changes are greater than 100 mils but less than 200 mils
What does GTL stand for?
Gun Target Line
What is the nomenclature for the complete 60mm mortar system?
M224A1
What is the nomenclature for the 60mm mortar cannon?
M225A1
What is the nomenclature for the complete 81mm mortar system?
M252A1
What is the nomenclature for the 81mm mortar cannon?
M253
What is the nomenclature for the 120mm cannon?
M298
What is the nomenclature for the aiming circle?
M2A2
What is the nomenclature for the 81mm old baseplate?
M3A1
What is the nomenclature for the 81mm new lightweight baseplate?
M3A2
Which boresight is used on the 81mm and 120mm mortar systems?
M45
What is the nomenclature for the green aiming pole light?
M58
What is the nomenclature for the orange aiming pole light?
M59
What is the nomenclature for the 60mm large round baseplate?
M7A1
What is the nomenclature for the 60mm mortar square baseplate?
M8
What is the nomenclature for the 60mm small round baseplate?
M8A1
What is the nomenclature for the 120mm baseplate?
M9A1
What is the mortar platoon's mission?
Mission is to provide close and immediate indirect fire support for maneuver battalions and companies.
What does MFCS stand for?
Mortar Fire Control System
What is the only authorized position for 60mm WP and 81mm RP rounds to be stored?
Nose End Up / Fuse Facing Skyward
What is a short round?
Occurs when there is incomplete firing of the propelling charge explosive train, causing the round to be discharged under significantly reduced pressure
What is the color and markings on HE mortar rounds?
Olive Drab with Yellow Markings
Describe a Deliberate occupation?
Planned well in advance, able to conduct recon from ORP
What does PACE stand for?
Primary, Alternate, Contingency, Emergency
How many types of smoke missions are there?
Two Types
Under normal conditions, how far should the aiming posts be laid from the mortar system?
Under normal conditions the front sight post should be placed at 50 meters and the far post should be placed at 100 meters
What are HE mortar rounds used for?
Used against personnel and light material targets
120mm white phosphorus rounds can be stored in what two positions?
Vertical with the Fuse End Up or Horizontal
What is the color and markings on ILLUM mortar rounds?
White with Black Markings
Can a commander shift the priority of fires based on the threat?
Yes. He can assign priority of mortar fire to increase the effectiveness of direct fires. For example, the effectiveness of close-combat missiles can be increased by having mortar fire obscuring enemy overwatch elements, forcing enemy armor to close hatches, suppressing accompanying Infantry, and canalizing an enemy.
What are Smoke mortar rounds used for?
red or white phosphorus (WP) filler, is used as a screening, signaling, casualty-producing, or incendiary agent
The M67 sight is illuminated by what?
self-contained, radioactive tritium gas
What are TP/FRTR mortar rounds used for?
used when training squads and indirect fire teams (less expensive than service ammunition) or when the use of service ammunition is restricted
What is the nomenclature for the 120mm bipod?
M191
What is the nomenclature for the 60mm mortar lightweight bipod?
M170A1
What is the nomenclature for the 81mm old bipod?
M177
What is the nomenclature for the 81mm new lightweight bipod?
M177A1
How much does the M67 sight weigh?
2.9 pounds
What are the three phases in a quick smoke mission?
1.) Adjustment Phase 2.) Establishment Phase 3.) Maintenance Phase
What are the 81mm mortar pre fire safety checks?
1.) Cannon is locked to the baseplate, and the open end of the socket points in the direction of fire. 2.) Firing pin recess faces upwards. 3.) Bipod locking latch is locked, securing the cannon clamps. 4.) Leg-locking handwheel is hand tight. 5.) Check for Mask and overhead clearance.
What are the 120mm mortar pre fire safety checks?
1.) Checks for mask and overhead clearance 2.) Ensures the cannon is locked to the baseplate 3.) Ensure White line is skyward and centered on clamp handle assembly 4.) Checks the buffer housing assembly to ensure that it is locked. 5.)Checks the cross-leveling locking knob to ensure it is hand-tight. 6.)Checks the spread cable to ensure that it is taut. 7.) Checks the firing pin to ensure that it is properly installed in the breech cap.
Name the five events in a gunners examination?
1.) Mount the mortar 2.) Small deflection 3.) Large deflection 4.) Refer realign 5.) Reciprocal Lay
What are the 60mm mortar pre fire safety checks?
1.) The cannon is locked to the baseplate and the open end of the socket cap points in the direction of fire. The bipod should be connected to either the upper or lower saddle of the cannon. 2.) The cannon is locked on the collar by the locking knob. 3.) The locking nut is hand-tight. 4.) The selector switch on the cannon is on drop-fire. 5.) Check for mask and overhead clearance.
What is the lethal radius for 60mm mortar WP?
10 meters for WP
What is the max ord of the 81mm mortar?
10,000 ft. AGL
During a misfire all soldiers, except the gunner and squad leader, must move how many meters to the rear of the mortar system?
100 meters
What is the max ord of the 120mm mortar?
13,000 ft. AGL
What is the max range of a 60mm mortar handheld?
1340 meters
What is the sustained rate of fire for the 81mm mortar?
15 rounds/min
What is the max rate of fire for the 120mm mortar?
16 rounds/min for 1 minute
How many mils are within one degree?
17.7 mils
What are the names of the sheafs used in a mortar section?
Converged, linear, parallel, and special
What are the three types of mortar occupations?
Deliberate, Hasty, and Emergency
What are the two ways to fire without an FDC?
Direct Lay and Direct Alignment
What is the first thing done in the event of a misfire?
Everyone will announce "Misfire, Misfire, Misfire"
What does FPF stand for?
Final Protective Fires
What does FDC stand for?
Fire Direction Center
What measures are designed to make the rapid engagement of targets easy and at the same time provide safeguards for friendly forces?
Fire Support Coordinating Measures
What fuze setting is used for prone targets?
If exposed enemy troops are lying prone, the proximity fuze setting is most effective
What are the two types of smoke missions?
Immediate smoke and Quick Smoke
What fuze settings can used for standing targets?
Impact or near-surface burst fuze settings effectively engage exposed enemy troops that are standing
What does IVO stand for?
In Vicinity Of
Deflections use what rule?
Left Add Right Subtract (LARS) rule
What is the color and markings on RP mortar rounds?
Light Green with Black Markings
What is the color and markings on WP mortar rounds?
Light Green with Red Markings
What does LHMBC stand for?
Lightweight Handheld Mortar Ballistics Computer
Mortar rounds must be segregated by what?
Lot Number
Which boresight is used on the 60mm mortar system?
M115
What is the nomenclature for the 120mm ground mounted mortar system?
M120
What is the nomenclature for the 120mm vehicle mounted mortar system?
M121
What is the nomenclature for the aiming pole?
M14
What is the nomenclature for the 120mm Stryker mounted mortar system?
RMS6-L
Until the baseplate is firmly seat what must you do with the M67 sight prior to firing?
Remove the sight from the mortar
Azimuths use what rule?
Right Add Left Subtract (RALS) rule
What manual covers Mortars?
TC 3-22.90
What fuze setting is used for targets with overhead cover?
The delay fuze setting is most effective when an enemy is below heavily wooded terrain or in fighting positions with overhead cover
What is the primary role of mortars?
The primary role of mortars units is to provide a commander with immediately available, responsive, and both lethal and non-lethal indirect fires in support of company / troop and battalion / squadron maneuver.
What fuze setting is used for targets in open fighting positions?
The proximity fuze setting is also the most effective if an enemy is in open fighting positions without overhead cover
How are mortar rounds to be hung in the tube?
The round is fully seated and dropped under its own weight into the tube. The rounds are not thrown, pushed, or shoved down the tube
What is the tolerance in order for a mortar to be considered laid? What is the preferred?
There is a 2 mil MAXIMUM tolerance in order for the mortar to be considered laid. However 0 mil mortar laid is preferred for greater accuracy
How many phases are there in a quick smoke mission?
Three Phases
Describe a Hasty occupation?
Time critical decision made on the fly. Unit takes MFP by force without prior recon