The U.S. military continues to face a pilot shortage, and while the services may offer incentives to retain aviators, the Defense Advanced Research Projects Agency (DARPA), the research and development agency of the United States Department of Defense (DoD), continues to support unmanned aerial system (UAS) initiatives. This week, DARPA’s Tactical Technology Office (TTO) released a “request for information” for a drone that could carry nearly twice that of a Sikorsky CH-53K King Stallion.
The RIF for the “Cost Effective Cargo” called for “innovative and revolutionary concepts for heavy lift Uncrewed Aerial Systems (UAS) that are capable of lifting a 70,000lb payload utilizing current Commercial Off The Shelf (COTS) engines and drive train technology.”
DARPA isn’t looking for any firms to build a prototype but rather is seeking to gather the necessary data to inform and explore future programs that could build and then test such concepts at scale. The RFI also noted that “The government will comply with data rights assertions.”
Heavy Lift – Short Haul
Notable about the new RFI is that DARPA isn’t looking to find a replacement for the military’s long-range fixed-wing cargo aircraft. This is instead about short distances, such as moving large payloads between vessels at sea or to beachheads, while also being able to cross wide rivers and other obstacles on the land.
“The DoD has identified the need to solve the ‘ship to shore’ and ‘wide gap crossing’ problem. There are significant challenges in amphibious operations and land maneuvers, where armed forces must move troops, vehicles, and supplies from naval vessels to a beachhead and then across natural or man-made obstacles. These operations are complicated by the need for landing craft and amphibious vehicles to navigate shallow waters, avoid obstacles, and contend with enemy defenses,” the RFI explained.
It further noted that the speed of movement is a critical operational need, as delay in offloading “personnel and equipment” during ship to shore and other wide gap crossings can “expose forces to enemy fire,” while hindering the establishment of a secure foothold. Moreover, even once such a foothold is established, as forces move forward and inland, there are still rivers and ravines that need to be crossed. There are engineering solutions but those require time-consuming operations, which could provide an enemy time to prepare and respond. Weather and sea conditions were cited as impacting the safety and efficiency of landings, while there remains the threat from enemy defenses.
“Heavy lift UAS could offer innovative solutions to these challenges by providing a means to rapidly transport equipment, supplies, and large platforms. They can operate in various weather conditions and avoid enemy defenses more effectively, exploiting the latest intelligence while being responsive to changing battlefield conditions to deliver essential resources directly to where they are needed most,” the RFI added. “By using heavy lift UAS, forces can maintain operational speed, reduce vulnerability to attack, and ensure continuous logistical support, thereby enhancing the overall effectiveness of amphibious and land operations.”
It would seem that DARPA’s TTO understands the challenges that need to be overcome, and addresses the reasons why a larger manned rotary or even tilt-rotor aircraft may not be the solution. There are issues with power-to-weight ratio, airframe strength, developmental and operational costs, and crew safety. The TTO sees that UAS may offer a potential solution, and the drones could be developed to meet different priorities and provide mission profile flexibility – without the cost of crewed safety considerations while minimizing the training and certification time for pilots.
“DARPA is interested in identification of design insights and key risks that can be addressed within a scaled down form to further substantiate DoD investment in heavy lift systems and challenge the paradigm of current UAS design as a whole,” the RFI stated.
Not to Reinvent the Wheel
DARPA further stressed that it isn’t looking for submissions for designs or derivatives of current aerial solutions, including standard helicopters, multirotor copters, tail sitters, or jump platforms with wing kits.
However, there are no restrictions on internal vs. external cargo.
“The bottom line is that the US needs to move large and heavy cargo cheaply,” DARPA stated in the announcement. “Examples are moving a 40ft ISO container off a container ship 10 miles out at sea onto land, or a Bradley fighting vehicle from one side of a canyon to the other.”
The ongoing conflict in Ukraine has certainly shown the potential for small UAS, but it has also shown the complexity of crossing natural and man-made obstacles. Ukrainian forces have struggled to gain a beachhead on the opposite banks of the Dnieper River, and Russian fortifications in Crimea are still viewed as a significant barrier that would need to be crossed if Kyiv launches an offensive.
Likewise, as the U.S. continues to see a growing threat from China, the issue is how the U.S. military can secure beachheads on distant islands. The Cost Efficient Cargo project could help solve some of these problems.
Responses to the RFI are due December 20, 2024.
