The New MPAT Aound

The New MPAT Round The New 120-mm M830A1 MPAT round. with a proximity fuze Gives U. S. tanks anew weapon against helicopters by Sergeant First Class William Fogg and Staff Sergeant Robert Homer Over the next several years, the Army will be fielding anew HEAT round (Figures 1 and 2). This new HEAT round has both a full frontal impact switch assembly and a proximity fuze that will give Abrams crews an effective weapon against enemy helicopters. Unlike the current HEAT round, which detonates on contact with the target. the proximity fuze detonates the round when it is near the target. So, even a near-miss is likely 10 destroy the helicopter. A selector switch, set by the loader before chambering the round, arms the M830Al for either ground or air largelS. In ground mode, the new round performs like the current HEAT round. Introduction of the new round will be graduaJ, with fint priority going to units most likely 10 deploy. The round will require some hardware modifications to the fire conlrol system, including anew gunner's auxiliary sight reticle, gunner's primary sight lower panel, and revised ballistic infonnation. With its switch set to Ground mode, the MPAT round is designed 10 destroy lightly annored ground targets (the same as the M830), bunkers, buildings, the sides and rear of enemy tanks, and enemy personnel. M830A I cartridges will be shipped to units with the Air/Ground switch set to Ground mode. Engagement Techniques Gunnery techniques for engaging either ground targets or helicopter targets in the open is the same as for any other main gun round. Gunners place the AMMUNITION SELECf switch to MPAT (Figure 3), lay on the visible center-of-mass, lase, and, when given the command by the tank commander, fire. The loader either checks that the air/ground switch is set to ground (ground mode) or sets the Technical Data and Fire Commands "1JUIe Veloctly 1,410 metets per MeOnd Fuzing Sp:.m Point Inltiatlrlg a- oeton.tIng (ground rnocM). ProxImity or Poit'It initiating BaM Deton.tIng (air mode). Announeeclln Are Comll'lllnd...... p... r (ground modIi) "MP... T "'IR (air mode).......,."..,. UghtIy armored venle.... buildings, bunkers, anttt.nk lIuldMl rnlaslie I'" TOM) JNtforma,.nd penonnel s.conct.ry round few tIInk or tllnk-like t.rgets (ground mode)...... (-" mode). Colo<.- 8t.ck with yellow Iett1InI a-c...... rldnp See FlIII. I" 2 WoIght 50.1 pounOa 38.74 Inches _ht..... 1,000 IMteB 12 switch to air and announces "AIR" (air mode) then chambers the round and announces "UP" (Figure 4). tn air mode, a black cloud of smoke is produced when the round functions on a target. This smoke allows the firing tank or wingman to sense MPAT rounds employed against helicopters. In air mode, after the proximity fuze is fully enabled, the round will function on almost any object it detects. whether it is a target or not. lbere-fore, in a cluttered environment. it may be necessary to use an alternate aiming point to help ensure that the round does not explode before it is in the vicinity of the target. For example, if the target helicopter is hovering or flying close to a group of trees. the round may function on the near edge of the tree line; if the target helicopter is using the top or side of a building for cover, the round may function on the building. In either case, using an alternate aiming point increases the standoff between the clutter and the trajectory of the round (whether in deflection [2.5 mils] or elevation [2 mils]), and, therefore, increases the chance of the round functioning on the desired target. Figure 5 displays a deflection offset; Figure 6 displays an elevation offset. An MPAT round fired in air mode at a ground target will probably explode before reaching the target. Degraded Mode Gunnery Pan of the fielding of the MPAT in-eludes new GAS reticles. These new

• 5 6 vTtn coo.·ou MPAT ® lVdVIJ

2. Loade.· extracts round and begins to tum toward gun.

3. Door starts to dose two seconds aftRrdernHnOves knee from switch •

4. Loader checks andlor sets Air/Ground Switch and announces AJR if setting the switch to AIR.

5. Loader swings around toward breech.

6. Door is closed. Loader rams round, moves SAFE-ARMED handle to ARMED position (up). clears path of recoil, and announces UP. Figure 4. MPAT Loading Sequence 13

5. Deftection Offset reticles provide the capability to fire SABOT. STAFF. MPAT. and HEAT rounds (Figures 7 and 8). Gunners firing MPAT using the GAS against moving targets should apply a standard lead of 2.5 mils (compared to 5.0 mils for HEAT). The XM-943 STAFF round will be fielded at a later date. lbe stadia reticle pattem will be in· c1uded on both reticles. If the laser rangefinder is inoperative. the stadia reticle may be used to determine the range to a target. The pattern has a base line and a series of range lines for full-height targets (Figures 9 and

10) and a series of dots for ranging at a target in turret defilade. lbe reticle is sca1ed to a 2.41-meter fully exposed target and a 0.89-meter turret. If the target has a different height, the accuracy of the range de· termined will be degraded accord· ingly. Air Search While crewmembers scan their assigned sector for ground targets, they must also be aware of air targets. To aid in the detection of air targets. crews should use the horizontal or vertical search technique described in FM 17·12-1· 1. Chapter 6. Crewmem- 14 Elevation 0t'T5et bers should periodically search their assigned sector using the rapid scan method to check air space above the sector. As each crewmember com· pletes a rapid scan across the sector and his field of view meets the horizon. he should switch 10 a detailed search and make a careful, deliberate... AT

4.::::::C.,- -,.'._--' • --<>- • · _.-.

•. -+- · -.-.

•. -t- · +-: -. +. -. t • Figure 7. MPAT/HEAT Reticle search of tree lines, valleys. and possible air corridors silhouetted by distant background terrain. Attack helicopters try to engage al extremely long ranges, therefore. target identification is difficult. Crews must make every effort 10 identify the target correctly (identify friend. foe. t_ ••. ":".... - -!,..l -+-.::--.......,----: =:::::l===.. -.. -.- -+-0'... _.-. t--. t· -. 1 • Figure 8. KEiSTAFF Reticle

8 12 16 20 8 12 16 20 I 24 28 I I 24 28 I I - I I - I • • • • • • • • •

• •

• • • Figure 9. St.tia retic • Full height target Figure 10. StadWi reUcle - Target in turret defilade or neutral [JFFN]). To prevent fratricide. leaders must keep crews informed of friendly aircraft operating in their unit's sector. Based on mission, enemy. terrain and weather, troops. and time (MElT-n. lhe unit commander may establish air guard(s). An air guard is a designated tank (or tanks) with MPAT battlecarried in air mode; the air guard is pri. marily responsible for detecting and engaging aerial wgets. A crew on air guard searches for aerial targets in the same manner as other crews. Gunners search their assigned sector using the search and scan techniques outlined in FM 17-12- 1-1. Chapter 6, however: _ Sector limits established for the gunner must cover likely helicopter locations and avenues of approach. _ Gunners must ensure ground reference points ace always within their field of view. Tank Crew Gunnery Skills Test Once tanks have been upgraded. Sta· tion 2A (Identify 12()..mm ammunition and explain its use) will include iden· tifying and explaining the use of MPAT and Station SB (Load the 12()" mm main gun) will be added to in· clude loading SABOT. HEAT, MPAT (ground mode). and MPAT (air mode), The time standard for SABOT. HEAT, and MPAT (ground mode) re· mains 7 seconds. MPAT (air mode). on the other hand. is 8 seconds, Training A training support package will be made available to the trainer thaI will enable him to train MPAT. The training support package includes an up-- grade to the conduct--cf-fire trainer (COm. dummy rounds, video tape. and an MPAT training pamphlet. 'The training support package will be fielded to units receiving the M830A I MPAT round tank hardware upgrade. Conduct--cf-Fire Trainer (COfT) will be the primary means of training the complete capabilities of the MPAT round. Upgrades to COFf will occur in two phases. The phase I upgrade will permit engaging light annot targets using MPAT in the ground mode. and heli-Sergeant First Class William H. Fogg is currently assigned as the NCOIC of the Gunnery Training and Doctrine Branch of the U. S, Army Armor Center's 5th Squadron, 16th Cavalry. He has selVed as troop and squadron master gunner as well as platoon sergeant and first sergeant in the 3d Squadron, 11 th Armored Cavalry Regiment, and regimental master gunner in the 2d Armored Cavalry Regiment. Staff Sergeant Robert Homer is currently selVing as an armor gunnery doctrine writer with the Gunnery Training and Doctrine Branch, 5th Squadron, 16th Cavalry, Ft. Knox, Ky. Previously he selVed as a master gunner and tank commander in 2-64 Armor, Schweinfurt, Germany.

capler targets with MPAT in the air mode. In the air mode, the target hit plates have been expanded to simulate the effective radius of the proximity sensor. Ground mode operation will require a hit. The Instructor/Operator (UO) will have the capability to "LOAD" either air or ground mode based on the tank commander's fire conunand. The combination KEIST AFF and MPATIHEAT GAS reticles will not be available. This upgrade will be delivered to units starting in IQ FY 94 and will continue until the phase 2 upgrade is ready for distribution. Phase 2 of the COIT upgrade will provide a "full-up" MPAT capability. evasive helicopter targets. clutier effects. bunker targets, and KFJST AFF and MPATIHEAT GAS reticles. This upgrade should begin distribution about 3Q FY 95. Thiny M830A I dummy rounds will be produced for each tank banal ion and 22 for each cavalry squadron. 'These will be distributed lhrough the Training Suppon Center (TSC) and will be available before units receive MPAT rounds. If a dummy round becomes unserviceable, units should n0- tify their local TSC. The MS30A I MPAT training video will demonstrate the MPAT capabilities and crew duties. One tape will be mailed directly to each battalion-size unit that is fielded with MPAT before January

1994. Afler that date. units will be able to order the video through their local TSC. The MPAT training pamphlet will be distributed directly to units receiv· ing the MPAT round until the completion of the MPAT fielding plan. The pamphlet describes engagement procedures for MPAT, revised Anna· ment Accuracy Check (AAC) Data and Computer Correction Factors. 15