10 to 80: A Refocused Approach to Mobile Gun System Maintenance for Stryker Brigade Combat Teams

Stryker brigade combat teams (SBCTs) across the Army struggle with main taining the readiness of the Mobile Gun System (MGS). While plagued by difficulties in diagnosing faults, a train ing shortfall for operators and main tainers and along lead-time for parts, MGS offers a unique long-range direct-fire capability unmatched in a SBCT and critical to the formation. In June 2019, 4th Squadron (Longknife), 3rd Cavalry Regiment, recognized that a fundamental shift in how we maintained the MGS fleet was needed. We developed anew three-pronged ap proach to MGS maintenance by focus ing on training our maintainers on MGS-specific processes, pulling turrets to reset wiring and teaching operators more advanced maintenance. Through this new methodology, Longknife Squadron increased readiness from 10-percent fully mission capable (FMC) to 80-percent FMC in just six months. We also recognized particular issues pertaining to Multiple Integrated Laser Engagement System (MILES) use on the MGS and institutional challenges SBCTs face that may prove valu able to our sister SBCTs throughout the Army. Lessons-learned Misdiagnosis or no diagnosis: importance of MGS-specific training for 91Ss. The first issue identified was a platform-specific training shortfall among the military-occupation spe cialty (MOS) 91S population responsible for maintaining the fleet as well as the MOS 19D vehicle operators. Thus the initial solution focused on training both the maintainers and operators. Field-support representatives (FSRs) from private industry traveled to Fort Hood, TX, with the purpose of training the 91S population on diagnosing MGS faults. Most faults that historically stymied our 91S team related to MGS-unique computer systems (line-replaceable units or LRUs) and their associated wiring harnesses. The knowledge gap on the MGS fleet produced long trouble-shooting times and often-incorrect diagnoses. This led to even longer down times and unnecessary spend ing due to incorrect-parts purchasing. Only upon installation of the incorrect part and persistence of the fault would the mechanics realize the error of their initial diagnosis and move onto another diagnosis. FSRs were able to help familiarize our 91S with the function of each LRU, the pinout chart on the wiring harnesses that led to that LRU and how to trace a fault across the complex architecture of the MGS firing system. While this training helped improve our diagnostic effectiveness, it alone was not the solution to MGS readiness, and it did nothing to address operator training. Pulling turrets: an accelerant in oper ational readiness (OR). In September 2019, the squadron brought in two FSRs from private industry at Joint Base Lewis McChord, WA, to support our gunnery. These contractors initial ly supported instructors from Fort Lee (VA)’s Ordnance School who were part of the Unit Diagnostic Immersion Pro gram (UDIP). This team continued the focus on maintainer education (fault identification and troubleshooting) and then expanded to include opera tor education. This FSR team astutely observed that nearly all the turrets had misaligned, incorrectly routed, broken or outright incorrect cables in side and around the turret. Time-consuming (manhours and long lead times) and expensive to replace, these non-mission-capable cables were crip pling the fleet. Over the years, un trained mechanics and unfamiliar operators moved and replaced cables, slowly creating this problem. Compounding the issue in Longknife Squadron is the fact that ever since the MGS refit in 2017, our MGS fleet is mixed – meaning that seven MGSs have improved turrets and five have unimproved turrets. While the differences in operating MGSs are indistinguishable, the wiring disparities are significantly more nuanced. LRUs are interchangeable between improved and unimproved turrets, but their associated wiring harnesses are either shorter or longer depending on the turret type. Installation of the wrong cable for the turret type usually re sults in the cable being broken. Based on the FSR’s recommendation, the squadron conducted a fleet-wide turret pull and reset – something nev er completed in 3rd Cavalry Regiment because the turret pull is not a task included in the MGS services plan. It typically takes about five working days with two mechanics and a three-per son crew supporting the operation to remove, rewire and reattach an MGS turret. With one 91S noncommissioned officer (NCO) supervising, the squadron maintenance team per formed up to two turret pulls simultaneously. Second benefit to turret pulls: train ing made easy for mechanics and op erators. Not only did the turret rewir ing accomplish the goal of reducing the number of broken cables, it also provided an invaluable training oppor tunity for our mechanics. The squad ron’s 91S NCOs built on training provided by the UDIP and FSRs to train new 91Ss on the more detailed issues of the MGS platform. The ease of training with a turret removed cannot be overstated. Rather than working with about eight inches on either side to find cables as the turret rotates, the turret is now accessible from every angle and cable routing is significantly easier to understand. Not to mention the ease in which we were able to in stall LRUs, reducing the install times significantly. We finally had the capacity to develop our own organic MGS-focused 91S maintenance team. Also, with a com plete rerouting of all the cables in the turret, mechanics could eliminate bad cables during the troubleshooting process. The decrease in troubleshooting time, coupled with a decrease in incor rectly ordered long-lead-time cables, helped contribute to the overall im provement in the MGS fleet OR rate. In addition to diagnostic training, operator training and the turret rewiring, the squadron fundamentally relooked the alignment of the maintenance personnel to better support the MGS fleet. Mechanics with advanced diag nostic training and turret-pull experi ence became habitually associated with the MGS platoons. This not only increased the depth of their knowledge, but over time they developed buy-in on the MGS problem. Also, when going to the field for training or gunnery, these mechanics were task-organized to the troop. Results come to fruition: 80-percent MGS OR. This three-pronged strategy of training, turret rewiring and alignment of mechanics worked in credibly well. After returning from National Training Center (NTC) Rotation 20-02, the MGS fleet’s OR stood at 10 percent. Before the NTC rotation, the average MGS OR for the year stood at 25 percent. By the start of holiday leave, the squadron maintenance team brought the OR up to 40 percent. In January 2020, the squadron imple mented the MGS turret pulls, and the OR steadily climbed to more than 80 percent, reaching that mark for the first time since fielding the vehicles. In early March, the weapons troop con ducted gunnery, putting the newly re wired vehicles through their paces. While the OR dipped to 50 percent during gunnery, constant field maintenance kept the vehicles participating in the gunnery. And, significantly, there were no new wiring-related faults during gunnery, thanks to the team’s excellent work during the pre vious two months. Coming out of gunnery, the OR rate climbed back to 80 percent as replacement parts arrived and mechanics in stalled them. MILES: an MGS Achilles heel? In addi tion to miswired turrets causing dead lined MGSs, the squadron also ob served a strong correlation between the use of MILES gear and the failure of MGS systems, specifically the turret electrical components. Initially, noticing a high failure rate of these components during training events involving MILES gear, we began to keep track of those faults more closely. Our mainte nance team used a multimeter to see if installing MILES gear caused irregu larities with the turret electronics. They took many samplings of voltage at key nodes throughout the turret and noticed that with MILES gear in stalled, there were extreme voltage irregularities. Over the course of an entire training cycle, the weapons-troop executive officer and maintenance team tracked faults diligently and broke them into the training periods. Figure 2 demonstrates that during periods of training where MILES gear was used, the MGS fleet suffered a significantly higher number of faults related to components that ran purely off turret power than during periods of similar training without MILES gear. The team attempted to strengthen the validity of their initial hypothesis by comparing training events (featuring similar times and types of movement and turret use), reducing the difference to the presence or absence of MILES. While no two training events are identical, Figure 2 clearly shows a higher incidences of turret electronic faults with MILES installed. Key among the turret electrical faults was an irregular number of thermal optic burnouts, LRU failures and asso ciated wiring harnesses shorting. Also, in some vehicles the entire slip ring shorted out, causing electrical arcing Figure 1. MGS OR in Longknife Squadron, Dec. 3, 2019-April 1, 2020.

within mere hours of MILES gear installation. MGSs that performed per fectly for months of training before MILES use would inexplicably be dead lined almost as soon as MILES gear was installed. To combat the issue, after a troop sit uational-training exercise (STX), the regimental commander decided to no longer use MILES gear on MGSs until NTC. This was when the correlation became painfully clear. During pre-de ployment operations at the rotational-unit bivouac area, the weapons troop screened (zeroing of the MGS main weapon) seven out of the nine MGSs with no issues. At the completion of force-on-force operations, two had shorted slip rings (a very rare dead line), two had burned-out command er’s thermals, one had a burned-out gunner’s thermal and three had either LRUs or wiring harnesses shorted. Leading up to the NTC rotation, turret electrical faults were observed 28 times during periods of MILES use, as opposed to only nine times during pe riods when MILES was not used. While correlation often does not equal causation, this specific instance of cor relation, coupled with voltage irregu larities observed by mechanics, certainly suggests that MILES gear induces faults in the MGS turret electronics. Therefore, Longknife Squadron at tempted to determine if this was an Army-wide issue; many sister weapons troops reported they had the same ex perience -- also stating they did not have operational MGS MILES equip ment, which raised the question of whether MILES itself is inherently faulted or if the problem is degraded MILES equipment causing issues. It is without question that this topic needs further exploration and could be an article unto itself, but Longknife mitigated the issue by only using MILES when absolutely necessary (mainly combat-training-center rota tions), disconnecting it as soon as possible and using observer-controllers to adjudicate whenever possible. Institutional MGS issues (and thoughts on overcoming them) There are several institutional challenges facing the MGS outside of the discussion about its pending obsoles cence. There is no specific MOS for MGS operators; 19D troopers operate the MGS in Longknife Squadron and most other SBCTs. These same troopers, with the same training, serve as dismounted scouts in our line cavalry troops. Most 19Ds we receive for the MGS platoons have absolutely no MGS experience and, at best, minimal time on a Bradley Fighting Vehicle (BFV). Being entirely new to the platform with little to no experience operating a turret presents a tremendous challenge for understanding the proper operation and maintenance of such a complicated piece of equipment. Even if Soldiers have previous experience on the Stryker platform, the MGS is al most an entirely different system. We recommend that the Army either institutes an additional-skill identifier (ASI) for 19Ds who have turret experi ence, either on a BFV or MGS, or ad just the modified table of organization and equipment for MGS operators back to MOS 19K. While having a spe cific MOS for MGS vehicles would be the most preferred course of action, this isn’t likely feasible due to the minimal number of MGS platforms vs. armor platforms in an armor BCT. A second personnel challenge with the MGS is the lack of an ASI for the 91S community. Mechanics in MOS 91S perform maintenance on all 13 vari ants of Strykers. While 80 percent of Stryker components are common across each variant, the other 20 per cent involve extremely complex elec trical and mechanical differences. There is no way to track who has MGS experience and ensure that SBCTs are able to put those skills to use in the weapons troop. There should be a series of ASIs to support the three most complicated and unique Stryker minority variants: the MGS, the anti-tank guided-missile vehicle (known as an ATVV if it has double-V hull) and the nuclear, biological and chemical reconnaissance variant. Creating these ASIs would allow strength managers and commanders the opportunity to put their mechan ics’ previous experience and knowl edge to good use supporting unique protection assets as well as the plat forms with the most firepower in the entire brigade. Training shortfall There is also a training shortfall on the MGS for new MOS 91S Soldiers arriv ing to the unit from advanced individual training. Therefore we recommend members of each class take a more indepth “elective training” on the minority Stryker variants. For the MGS, this training would include a turret pull, the discrepancies between im proved and unimproved turrets, and Figure 2. Longknife’s sampling of turret electrical vs. non-turret electrical faults during MILES use April-October 2019.

diagnostic/troubleshooting training to better prepare them to work on the

MGS.

The other variants each have their own maintenance challenges, which the training could address. This strat egy nests with the ASI assignments, which employs Army personnel systems to assign the mechanics with the proper training to the units with those variants. The prevalence of long-lead-time parts for the MGS contributes to the historically low OR. MGSs have many unique parts, which – coupled with their low density across the Army – creates a low demand. We have three turret pulls to complete, which are paused solely to receive long-lead-time parts requiring removal of the turret for installation. Many of the LRUs, any of the main turret-wiring harnesses and the Commander’s Panoramic Viewer and Hazardous Incident Response Equipment Sensor (the commander and gunner thermals, respectively) have at least three- to six-month lead times. Also, the squadron waited nine months for an MGS Forward Unity Periscope (FUP) to arrive from the re pair-part program. This vehicle re mained deadlined for that entire period. It is not financially advantageous to keep an MGS FUP in the shop-stock list, and one is not included on the SBCT critical-stockage list. This is an issue with most of the MGS parts – the pending obsolescence has caused many manufacturers of MGS-specific parts to shut down new production. If they do not have apart on hand, they require that the faulty part be turned into the repair system, and then end-users must wait for it to be refurbished. One potential solution to speed up acquisition of wiring harness for MGS is to have them locally fabricated or re paired. While the tools and knowledge are not resident in the SBCT mainte nance structure, local vendors have the capability to fabricate or repair the wiring harnesses. However, we were unable to leverage these resources due to the proprietary nature of the wiring harnesses, which prevented the availability of the schematics necessary to replicate or repair them. Conclusions While the Army continues to assess the MGS’ future, there are still best practices units can implement to bol ster readiness:

• A strong training program for both operators and maintainers is the foundation to success.

• Only choose the most technically proficient and resilient troopers as MGS operators and maintainers.

• Also, every SBCT weapons troop’s service plan should require turret pulls annually. If nothing else, this provides the chance to train new MOS 91S troopers and gives operators a chance to clean out the vehicles’ hulls.

• MILES gear should only be used when absolutely necessary, and MILES personnel should be trained to install and troubleshoot the equipment. With that in mind, Longknife Squadron attacked the problem of essentially only one platoon’s worth of MGSs FMC by using the concept outlined here. While the OR still is not 100 percent, an air of confidence and optimism now exists as the rate steadily trends upward. In just nine months, the squadron lifted the stigma of the MGS and it is now a true force-multiplier, sought after by the other squadrons in the regiment for its lethality and di rect-fire capabilities. LTC Rafael Morrison commands 4TH Squadron, 3rd Cavalry Regiment, Fort Hood, TX. His previous assignments include aide-de-camp to the command er, U. S. Forces Afghanistan/Operation Resolute Support, Kabul, Afghanistan; cavalry squadron S-3 and observer/ coach/trainer (O/C/T), Joint Readiness Training Center (JRTC), Fort Polk, LA; brigade S-3 O/C/T, JRTC, Fort Polk; brigade executive officer and O/C/T, JRTC; brigade S-3, 1ST Stryker BCT, 1st Armor Division, Fort Bliss, TX; and squadron S-3, 1st Squadron, 13th Cavalry Regiment, 3rd BCT, 1st Armor Division, Fort Bliss. LTC Morrison’s military schools include the Command and General Staff College, and the Maneuver Captain’s Career Course. He has a bache lor’s of science degree in agriculture from Southern University and A&M College, and a master’s of science de gree in public administration from Central Michigan University. LTC Morrison also is a recipient of the bronze medallion, Order of St. George. MAJ Nicholas Barry is the executive officer, Longknife Squadron, 3rd Cavalry Figure 3. A rewired MGS turret sits on a turret stand in the Longknife Squadron motorpool. (Photo by 1LT John Formica)

Regiment, Fort Hood. Previous assign ments include chief of operations, 3rd Cavalry Regiment, Fort Hood; assistant professor of electrical engineering, U. S. Military Academy, West Point, NY; O/C/T team chief, First Army Division West, Fort Hood; commander, Company A, 40th Engineer Battalion, 170th Infantry BCT, Baumholder, Germany; commander, Headquarters and Head quarters Company, 40th Engineer Battalion, 170th Infantry BCT, Baumholder; and construction officer, 326th Engineer Battalion, Fort Campbell, KY. MAJ Barry’s military schools include Command and General Staff College, Joint Engineer Operations Course, Sapper Leader’s Course, Pathfinder Course, Air-Assault Course and Airborne School. He has a bachelor’s of science degree in electrical engineering from the U. S. Military Academy, a master’s of science degree in electrical engineering from Rensselaer Polytechnic Institute and a master’s of science de gree in engineering management from Missouri University of Science and Technology. 1LT John Formica is the S-4, Longknife Squadron, 3rd Cav, Fort Hood. His pre vious assignments include executive officer, Quicksilver Troop, 4th Squadron, 3rd Cav; and cavalry-scout platoon leader, Task Force Nomad, Operation Inherent Resolve, Iraq. His military schools include Sabalauski Air-Assault School, U. S. Military Academy, Armor Basic Officer Leader’s Course, Army Reconnaissance Course, Stryker Lead er’s Course and Troop Executive Officer Course. 1LT Formica has a bache lor’s of science degree (dual major) in international studies (with honors) and international legal studies from the U. S. Military Academy. He is are cipient of the black medallion, Order of Saint George. Figure 4. An MGS from Longknife Squadron engages simulated enemy combat vehicles during force-on-force training under live-fire conditions during NTC Rotation 20-02. (U. S. Army photo by 1LT John Formica) Acronym Quick-Scan ASI – additional-skill identifier BCT – brigade combat team BFV – Bradley Fighting Vehicle FMC – fully mission capable FSR – field-support representative FUP – Forward Unity Periscope JRTC – Joint Readiness Training Center LRU – line-replaceable unit MGS – Mobile Gun System MILES – Multiple Integrated Laser-Engagement System MOS – military-occupation specialty NCO – noncommissioned officer NTC – National Training Center O/C/T – observer/coach/trainer OR – operational readiness SBCT – Stryker brigade combat team STX – situational-training exercise UDIP – Unit Diagnostic Immersion Program