In the final months of World War II, the Japanese military was logistically exhausted. At the beginning of the war, Japan had distributed troops throughout the Pacific, hoping to stall the U.S. Navy’s advance and force a clash of fleets that would rapidly decide the fight in its favor.1 Instead, the United States systematically overwhelmed or bypassed these garrisons on its steady march to victory. Just nine months after the attack on Pearl Harbor, underequipped and malnourished Japanese troops in some places struggled to sustain defensive operations. Logistical support collapsed under the steady threat of U.S. submarines and airstrikes.2 This was the inevitable result of Japanese planners’ deliberate inattention to what they saw as the banal requirements of operational logistics.3
The Marine Corps today has a better appreciation for logistics than World War II Japan did, but sustaining low-signature distributed forces conducting expeditionary advanced base operations (EABO) will be an enormous challenge. Recent publications such as Installations and Logistics 2030 and an update to MCDP 4 Logistics continue to emphasize the critical role of logistics while highlighting emerging shortfalls. Moreover, force-design initiatives continue to seek new and novel systems to improve maritime sustainment. A proposed new medium landing ship (LSM) is intended to sustain Marines in contested littorals, while revolutionary unmanned aviation logistics systems would enable lightweight, short-range air delivery.
Current concepts for future logistical sustainment heavily reference the LSM, but its fielding is in doubt, despite it being identified as a requirement five years ago. In December 2024, the Navy canceled a request for proposals because of the unexpectedly high industry bids for the envisioned vessel.4 Even before this cancellation, the first LSM was not expected to be in service until at least 2029.5
For now, existing surface connectors will continue to play an important role in logistical support, especially where small units are stationed on dispersed islands. But unmanned aerial logistics systems are becoming more capable, and the problems at U.S. shipyards make their development more urgent. These systems can help carry the load, especially where the stretches between islands prevent ground transportation after offload.6
Small- and medium-sized unmanned logistics aircraft provide capability at the tactical level but have neither the range nor the payload to mitigate the speed and scale vulnerabilities of surface connectors. Fortunately, the Marine Corps recognizes it has to close this gap while also bolstering the utility of crewed aircraft. The service’s large unmanned logistics systems-air (ULS-A) initiative answers this requirement.7 Because this initiative is in its infancy, it is crucial right now to correctly identify the capabilities the system must incorporate and the pitfalls to avoid in its design.
Identifying Speed and Range Shortfalls
EABO is a concept for use in any theater, but China’s influence on its creation is impossible to ignore. Any potential conflict with China would span a vast geography. For perspective, IndoPaCom covers more of the globe than any other geographic combatant command. The South China Sea, a focal point of regional tension, is only a small part of this total area but covers a staggering 1.4 million square miles.8 With established bases at a premium and much of the area covered by water, the ability to conduct logistical sustainment at extreme range will be key to operational success.
To date, the Marine Corps has pursued various uncrewed aerial logistics initiatives. The small Tactical Resupply Unmanned Aerial System advertises payloads up to 150 pounds and a range of 9 miles. The Medium Aerial Resupply Vehicle-Expeditionary Logistics is larger and carries a payload of up to 600 pounds, but it is limited to a range of 100 miles.9
These aircraft can fill a short-range, light-payload niche but do not answer the most obvious challenge of operating in an environment covered by enemy antiaccess/area-denial systems. Distributed forces can dilute the effectiveness of China’s growing arsenal of precision long-range weapons. The distance between these forces, however, means that to be useful, an unmanned logistical aircraft must operate at long range, with substantial payloads, and at speeds unmatched by any surface connector. By defining the specific capabilities for a particular mission—aerial and ground refueling—it is possible to envision what the large ULS-A will need to do.
Aerial Refueling
A vertical-lift unmanned aircraft built to refuel rotary-wing and tiltrotor aircraft in flight would address other logistics capability gaps as well. In addition, ensuring a large ULS-A can operate from most of the Navy’s surface vessels would provide the flexibility future operating environments will require. An unmanned aircraft with a flight radius of 350 nautical miles, a payload of 10,000 pounds, and a speed of 215 knots would satisfy these demands.
The ability to refuel aircraft in flight is a force multiplier during operations that rely heavily on aviation—as will be the case when aircraft must provide logistical sustainment to distributed forces at long ranges. Vertical-lift aviation could support austere sites that have limited infrastructure and may not include a hard-surface runway. Unfortunately, currently only one model of aircraft in the Department of Defense, the C-130, can refuel rotary-wing aircraft.10 The Marine Corps’ KC-130Js are few and high in demand, and these aircraft would be heavily tasked in a western Pacific contingency.
An unmanned aircraft with a payload of 10,000 pounds of fuel could add roughly three hours to the flight of a single CH-53. Rotorcraft such as the CH-53 refuel at speeds of only about 120 knots. But an unmanned vehicle able to fly at 215 knots also could refuel V-22s, and if equipped with a variable-speed drogue, it could support the needs of multiple aircraft without having to land and reconfigure drogues.11 Refueling support would be most effective if fielded at a scale that allowed multiple unmanned aircraft to hold at refueling tracks distributed along extended routes.
Air-Delivered Ground Refueling
A large, unmanned logistics aircraft also could refuel rotary-wing aircraft that cannot refuel in flight. The Marine Corps’ AH-1Z and UH-1Y fleets have limited endurance and rely on forward arming and refueling points to “increase the operational reach . . . increase sortie-generation rates in operating areas, and increase flexibility in the use of aviation.”12 Requirements to establish rearm and refuel points for these aircraft can be extensive, and these operations could erase many of the low-signature advantages of EABs. Procuring fuel from host nations has been proposed, but this alternative rests on shaky assumptions of unfettered access, adequate quantities, and acceptable fuel quality. With a 10,000-pound fuel capacity, a large ULS-A could service four H-1s in support of distributed stand-in forces.13
Fuel is only one critical need for offensive aircraft operating from sites with limited infrastructure. During a naval campaign, these aircraft may need to rearm more often than they refuel.14 An unmanned vehicle capable of transporting 10,000 pounds of fuel could be configured to transport the same weight in ordnance. This would be crucial when there is a lack of embarked ordnance Marines and would align with Force Design requirements to limit redundant support personnel. A former Marine Corps air group commander recently advertised the ability of H-1 aircrews to rearm and refuel themselves after supplies were airdropped to them in training.15 The Marine Corps must field systems that address the limitations facing its fleet of rotary-wing aircraft, or the H-1 upgrade program will represent a tremendous opportunity cost to Marine aviation.
Additional Considerations
The speed, range, and payload requirements for aerial and ground refueling give a clear picture of what the Marine Corps needs from a large ULS-A. The capabilities proposed here aim to mitigate the speed disadvantage of future LSMs if they do arrive, fill the logistical gaps left uncovered by slated unmanned aviation systems, and ensure combat systems are relevant in the battlespace.
The future large ULS-A must be capable of vertical takeoff and landing to enable maximum flexibility and ensure support for vertical-lift platforms, but a conventional rotary-wing design could not reach the required speed of 215 knots. While a tiltrotor concept could be fast enough, it might be too wide to operate on smaller naval surface vessels. The solution might be a novel design that can fold its wings along the long axis of the fuselage and fly like a conventional fixed-wing aircraft, its propellers acting as rotors during takeoff and landing. The startup PteroDynamics already has tested a smaller version of such a design on board the USNS Burlington (T-EPF-10).16
The design could incorporate an empty fuselage that accommodates a crane-like attachment, a concept already in use by Elroy Air’s Chaparral. Interchangeable pods would lock into the airframe to transport fuel, ordnance, or equipment to meet the specific logistical needs of EABs.
NMESIS Mobility
The Marine Corps is investing heavily in the unmanned NMESIS antiship missile system to target enemy surface fleets, but it, too, is limited in tactical application by the current lack of logistical sustainment.17 This is another use case for the large ULS-A. Each Naval Strike Missile weighs 2,200 pounds, so four connected missile modules locked into an aircraft crane system would fall below the established 10,000-pound limit. In addition, the crane design would eliminate the need to offload with ground-support equipment.
Squadron Structure
Effective fielding will rely on deciding which units will operate the large ULS-A. The most logical answer would be to integrate them into organizations trained in air-delivered logistical sustainment. Marine heavy-lift helicopter squadrons fly the CH-53E, which is being replaced by the CH-53K. A large unmanned logistical aircraft could handle many of the CH-53’s tasks at a much lower cost. There is a precedent in naval aviation for integrating manned and unmanned aircraft—fielding MQ-8C Fire Scouts in MH-60S squadrons.18 Using unmanned systems for logistics missions within an adversary’s weapon engagement zone reduces the risk to aircrews.
Affordability
Funding this aircraft will be a challenge all its own, but there are ways to avoid the financial pitfalls of previous programs. The Replicator initiative, while still inchoate, should develop new templates for procuring unmanned systems. The program aims to enable a competitive market-based cycle and reduce requirements for the government to directly fund research and development.19 The resulting reduction in unit cost for future systems could make potential battlefield losses increasingly sustainable.
Current Marine aircraft tasked with logistical sustainment are capable but were designed for conflicts against different adversaries. These aircraft are by no means obsolete. But the United States cannot stop at incrementally improving legacy platforms. The U.S. military is exiting an era of unchallenged military primacy. It cannot assume a qualitative advantage that it holds before a conflict will endure for its duration. The introduction of a large, unmanned logistics system will be critical to the successful sustainment of distributed forces in a future peer conflict.
1. Cathal Nolan, The Allure of Battle: A History of How Wars Have Been Won and Lost (New York: Oxford University Press, 2017), 540.
2. ENS William Harris, USN, “The Silent Service’s Success in the Pacific,” U.S. Naval Institute Proceedings 139, no. 6 (June 2013).
3. Osamu Tagaya, “The Imperial Japanese Air Forces,” in Why Air Forces Fail, Robin Higham and Stephen Harris, eds. (Lexington, KY: The University Press of Kentucky), 2016.
4. Geoff Ziezulewicz, “Marine-Moving Medium Landing Ship Critical to China Fight Put On Hold Again by Navy,” The War Zone, 20 December 2024.
5. Justin Katz, “What We Now Know About the Marine Corps’ Plans for Medium Landing Ship,” Breaking Defense, 13 March 2024.
6. Nolan Vihlen, “How Can the Marines Learn From the Falklands War?” War on the Rocks, 23 November 2022.
7. “ULS-A Guiding Principles and Mission,” PowerPoint Presentation. Headquarters Marine Corps Capabilities Development Directorate, November 2023.
8. Benjamin Sacks, “The Political Geography of the South China Sea Disputes,” RAND, October 2022.
9. Brett Davis, “Navy Demonstrating Programs for Drone Delivery at Sea,” Inside Unmanned Systems, 24 August 2023.
10. Joint Air and Space Power Community Air-to-Air Refueling, Joint Air Power Competence Centre, “Air-to-Air Refueling Matrix:” coi.japcc.org/aar/#matrix.
11. “Refueling Drogues,” Aerial Refueling, Eaton, 2021: www.eaton.com/us/en-us/catalog/aerial-refueling/refueling-drogues.html#tab-2.
12. Department of the Navy Headquarters, United States Marine Corps, Tentative Manual for Expeditionary Advanced Base Operations, 2nd Edition, 7-12.
13. GEN David Berger, USMC, A Concept for Stand-in Forces (Washington, DC: Headquarters Marine Corps, December 2021), 4.
14. Berger, Stand-in Forces, 7-13.
15. James Deboer, “The Compelling Case for the AH-1 Cobra in a Fight With China,” The War Zone, 22 March 2023.
16. Matthew Graczyk, “Seeing Is Believing: Transwing Flies at Sea,” PteroDynamics, 30 January 2024.
17. Peter Ong, “USMC NMESIS and Naval Strike Missiles Logistics Explained,” Naval News, 11 January 2022.
18. Richard Burgess, “Navy Is Sustaining 10 Operational MQ-8C Fire Scout UAVs; Rest in Storage,” Seapower, 31 January 2023.
19. Christian Brose, “Moneyball Military: An Affordable, Achievable, and Capable Alternative to Deter China,” Hoover Institute, 26 September 2023.