Roadside bombs have claimed the lives of hundreds of marines who were protecting convoys en route to replenish forward operating bases with water, food and supplies. Officials want to take trucks and troops off the roads in Afghanistan by relying instead on unmanned helicopters to deliver the cargo.
Following successful demonstrations of the concept with commercial technologies, the Marine Corps is pushing ahead with plans to rush a system to the front lines.
Naval Air Systems Command in May released a notice of its intent to conduct a competition for the procurement of a cargo unmanned aircraft system capable of carrying sling loads weighing at least 750 pounds.
The command has received responses from industry and it is anticipating the release of a request for proposals this month.
“We are looking to procure one system, which includes two air vehicles, an associated ground station and support equipment,” wrote Eric Pratson, cargo UAS integrated product team lead, in response to questions from National Defense.
The contract will be awarded about six months following the release of the RFP and deployment of the system is expected within nine months of the award, he said.
“The effort is a military utility assessment of a viable system,” he added.
A company of marines at a forward operating base typically needs 10,000 to 20,000 pounds of cargo delivered each day.
The Marine Corps Warfighting Laboratory earlier this year conducted resupply experiments with two autonomous helicopter systems at Dugway Proving Ground, Utah. The team tested Kaman Aerospace Corp.’s K-MAX and Boeing’s A160 Hummingbird in missions that included delivering 2,500 pounds of cargo over a distance of 150 nautical miles within a six-hour period.
Kaman partnered with Lockheed Martin Corp. to turn its piloted helicopter, employed by the logging industry since the 1960s, into an unmanned system. Boeing’s aircraft was designed as an autonomous intelligence, surveillance and reconnaissance platform, but it needed to be adapted for hauling cargo.
In the demonstrations at Dugway, one of the simulated forward operating bases was located at 4,300 feet to emulate the mountainous terrain of Afghanistan.
The two systems each had 72-hour preparation periods followed by three days of flight demonstrations. The sorties included one night flight.
“We gave them their missions every day” in a format that aircraft operators use in actual flight operations, said Marine Capt. Amanda Mowry, aviation combat element project officer and the immediate cargo UAS demonstration lead at the lab. During the sorties, the aircraft had to complete specific tasks, such as holding a hover at 12,000 feet for a minute with a load, and then continuing along the route and climbing to a higher altitude.
The UAS had to carry loads of standard-sized pallets measuring 40 inches by 48 inches and 67 inches in height.
“It forced the sling-load aspect of it,” said Mowry. “Marines work with pallets. They’re used to it. It set a baseline and they could adjust from there.”
Both systems completed successful demonstrations, she said.
The K-MAX carried 1,500-pound loads for every sortie except the final demonstration during which it carried almost 3,000 pounds distributed on a carousel of four pallets weighing 750 pounds each. “Not only that, they were able to drop them off at multiple locations,” said Mowry.
The Hummingbird carried 1,250 pounds on every sortie and was able to deliver the load accurately within three meters of the objective. “Once they literally landed on the stake and took it with them,” said Mowry. “They also flew a little faster.” The Hummingbird’s average speed with a sling load was about 80 to 85 knots. The K-MAX flew an average of 70 knots.
Both systems fly with more stability than a human pilot could provide at the controls, said Charles Johnson, a retired marine who flew CH-46 helicopters on active duty and now supports the lab as a contractor on the cargo UAS demo team. The systems are not affected by adverse weather conditions because they rely on sensors to prevent mid-air collisions. “A pilot can’t fly in mountainous terrain with fog or clouds or rain,” Johnson pointed out.
When the team began its initial foray into the project two years ago, it was told by government officials that cargo UAS technology was not feasible. But when the team sought input from industry last year, it received five proposals.
“Our desire was to be able to get a system over there yesterday, that could take these vehicles off the roads and resupply the marines that are out there,” said Johnson.
A typical resupply convoy might only have to travel 60 miles out and back, depending on the distance between forward operating bases. But that drive might take 16 to 24 hours with a caravan of 12 or more vehicles. One single UAS could carry 10,000 pounds of cargo in that same period, as the final demonstration sorties proved.
Both systems flew about 2,500 pounds of cargo in five hours, with K-MAX carrying 500 pounds more. “I think that was a good profile to show the operational capability of what we’re looking for,” said Mowry.
Being able to resupply marines with autonomous, beyond line-of-sight systems is critical because units may be dispersed in locations far from forward operating bases and safe landing zones for precision air-dropped supplies, said Johnson.
The team is investigating the possibility of using the cargo UAS as a casualty evacuation platform.