As the Army works through the validation of the Multi-Domain Operations Concept and begins constructing provisional task forces to fill these roles, it's important for contributors of the effort to have a full understanding of the capabilities and limitations of the units and forces arrayed. The proposed construct for the Multi-Domain Task Force (MDTF) includes helicopters and unmanned aircraft that will enhance maneuver, intelligence, protection, and sustainment.In this future concept, the aviation force may be dependent on a Brigade Support Battalion (BSB) for sustainment. This idea is not unheard of, as some divisions have already tried this method at combat training centers and in large-scale training events. A BSB supporting helicopters faces some unique challenges due to critical differences between the BSB and Aviation Support Battalion (ASB), in both design and capabilities. For instance, a quick comparison of the table of organization and equipment for a Stryker BSB and an ASB reveal a difference of almost 500 Soldiers, however, this aggregate number can be misleading without fully understanding the differences between the two units.Headquarters Company The headquarters for these two battalions are similar except for the support operations sections. The Support Operations Section in an ASB is augmented by a 153AL (Aviation Maintenance Officer), a 15Z (Senior Aviation Maintenance Supervisor), and a 15T (UH-60 Aircraft Repair Supervisor) who bring the necessary expertise for helicopters to the section. In the BSB, the brunt of the technical expertise comes from a 915E (Senior Automotive Maintenance Warrant Officer), a 92A (Automated Logistics Specialist, and 68Ws (Combat Medic Specialist).Imagine maintaining the brigade's equipment without the 915E, 68W, or the 92A in the BSB's SPO section. Is it possible? Yes. Is it a bad idea? Also yes. A force-tailored sustainment headquarters must have an aviation maintenance expert to help sustain and advise on aviation combat power. Aircraft are quite complex and airworthiness requirements drive key differences in field maintenance.Additionally, there are some other key differences within the Headquarters Company. With the recent Field Feeding Company Force Design Update, the ASB lost its organic field feeding capability and now requires external support, unlike the BSB. Furthermore, the ASB Headquarters Company has a 91-series automotive maintenance section because it is not large enough to stand alone as a separate company.Med Company A typical BSB brings a significant medical capability to a Brigade Combat Team (BCT). Among other health services, the Medical Company provides a field hospital and ambulatory transfer; however, the Medical Company in an ASB doesn't exist. The much smaller Medical Platoon, in the ASB's Headquarters Company, only has eleven 68Ws and two ambulances.The Combat Aviation Brigade's (CAB) primary ambulatory capability resides in the helicopter-borne unit of the General Support Aviation Battalion (GSAB). The Aviation MEDEVAC Company has some of the same goals as a BSB's Med Company: to provide casualty collection, lifesaving transportation, and en route care.Distribution and Supply The Distribution Company in an ASB is similar to the same company in a BSB. With 110 personnel and 140 trucks, trailers, and other rolling stock this company can operate a Supply Support Activity and distribute all classes of supply. There are some key differences; the ASB's Distribution Company has a slightly larger ammunition section, and the BSB's Distribution Company has a much larger Truck Squad and Water Section.The most significant distribution challenge for Aviation is fuel. The POL handling and storage capability (normally found in the BSB's Forward Support Companies [FSC]) are spread out across a CAB in order to better handle the massive amounts of fuel. This is where we see the disparity between a BSB's and an ASB's total number of personnel. If we subtract the FSCs numbers from a BSB, the ASB's 487 personnel is actually larger than the BSB's 411 personnel. Each FSC in a CAB is built into a helicopter battalion and modified to carry enough fuel for a specific aircraft. The Chinook burns the most fuel by far, and thus the FSC supporting the GSAB and the Chinook Company has 120 personnel and more than 80 pieces of rolling stock.The fuel use and handling requirements for a CAB are the primary cause for friction when a BSB is tasked to support a CAB. The helicopter battalions typically bring their own FSCs capable of maintaining operations forward of the support area. In a scenario where an entire CAB is conducting around-the-clock flight operations, the total fuel that the CAB will draw from a fuel point will stagger the normal support channels. In the ASB there is also a fuel/POL handling section inside the Aviation Support Company (ASC).Maintenance With nearly 300 personnel the ASC is larger than any FSC or Field Maintenance Company in a BSB. The ASC provides a field-level maintenance redundancy as well as a repair forward capability, a recovery capability, and a pass-back capability that ties the CAB to sustainment-level maintenance. The ASC is manned and equipped to repair helicopters and other aviation specific equipment, not ground vehicles. The rolling stock and generator maintenance in a CAB is performed by maintenance platoons or sections in FSCs and in the ASB's Headquarters Company.Repairing helicopters is similar in nature to repairing any other equipment. A key difference is that each type of helicopter has a dedicated occupational specialty for the repair. Additionally, there are seven specialties that repair aircraft components. The ASC has a repair section for AH-64, CH-47, and UH-60 as well as several component repair sections that support off-aircraft work.When building a MDTF the ASC's component repair capability must be factored. Engine work, rotor blade repair, RADAR and avionics repair, armament repair, night vision repair, and other maintenance is all performed by the ASC. The helicopter battalions in a CAB have Aviation Maintenance Companies (AMC), but these lighter and lesser-equipped companies cannot support all of the component repair work. Additionally, the major scheduled maintenance on a helicopter can sometimes take weeks to complete. The ASC is designed to conduct major scheduled and unscheduled repair work to allow the AMC and its parent helicopter battalion to remain mobile.Training Another significant discriminator between an ASB and a BSB is the way they train and validate unit readiness. BSBs deploy to combat training centers and execute sustainment operations as a battalion with their organic headquarters and supported battalions. Aviation units consistently task organize to support BCTs at a Combat Training Center (CTC). Platoons, sections, or sometimes individual personnel from ASBs are task organized with an aviation task force. During the short training rotations, the aviation force will simply operate without the component repair capability typically provided by the ASB.Each task organized battalion in the CAB rotates through a CTC supporting a BCT. The ASB is left without a collective training event in which to execute training and validation of their METL tasks. ASBs frequently coordinate and resource their own training exercises in order to adequately train and validate mission essential tasks. Balancing the ASB's training requirements, required aviation task force sustainment during CTCs, and garrison sustainment requirements for the remainder of the aviation brigade puts a significant demand on the ASB. Further, the ASB misses out on the experience and associated learning events that come with conducting battalion level planning, preparation, and execution for deployment, during CTC training rotations, and redeployment back to home station. With a shift to division-sized units of action and training for large-scale combat operations (LSCO), the ASB will play a more significant role in sustaining the aviation force than it has in the past. Ensuring the ASB has a collective training event as an organic formation allows Soldiers to gain proficiency and allows commanders to validate unit readiness.As the Army looks at restructuring to support the MDTF and best array forces for LSCO, it is important to consider the capabilities, design, and functions of each unit. In name and broader concept the ASB and BSB share much commonality. However, they are significantly different organizations with specific requirements that are not easily interchangeable. These differences must be realized and understood to ensure critical sustainment capabilities are not overlooked or misaligned.--------------------Maj. James Polk is Doctrine and Collective Branch chief at U.S. Army Aviation Center of Excellence. He has served as Sustainment Branch chief and in a variety of operational assignments at 82nd Airborne and 10th Mountain Divisions.Chief Warrant Officer 4 Dustin Case is a doctrine writer for U.S. Army Aviation Center of Excellence. He has served as aviation maintenance officer for 4th Battalion, 2nd Combat Aviation Brigade, and for 1st Battalion, 101st Combat Aviation Brigade.-------------------- This article was published in the January-March 2020 issue of Army Sustainment.