New Cargo Winch Saves CH-53K Program $60 Million
While trying to cut costs for the CH-53K King Stallion, the Marine Corps’ new heavy-lift helicopter platform, the H-53 program office found an obvious solution—the aircraft’s cargo winch, which was set to cost $350,000 each.
With the CH-53K fleet set to number 200 aircraft, the H-53 program office deemed a total cost of $70 million—not far from the $87 million it takes to build an entire King Stallion—too rich for a component Marines use sparingly on the current heavy-lift platform, the CH-53E Super Stallion.
In search of a more cost-effective alternative, now-retired Col. Hank Vanderborght, then-program manager of the H-53 Program Office, asked the Naval Air Warfare Center Aircraft Division’s Cargo and Special Operations team what they could come up with.
With a major assist from now-retired Gunnery Sgt. Peter Montalvo, who was mission systems crew chief for the H-53 program office, the cargo team found its solution on an industry shelf—the Warn 1500AC, an $800 winch capable of pulling 1,500 pounds. Even factoring in additional equipment needed to let the winch run off the King Stallion’s auxiliary power—and the expectation it would need to be replaced several times over the helicopter’s lifecycle—the winch is still expected to save more than $60 million, nearly 86 percent of the original winch’s price tag.
Stronger, Safer, Better
Navy and Marine Corps cargo aircraft currently are equipped with a centerline, hydraulic winch mounted in the forward part of the cabin, near the cockpit, and the initial plan was to install something similar on the CH-53K.
“The intent was to design a winch that would be permanently installed and never need to be replaced,” said Joe Holman, a mechanical engineer with the cargo team and lead on the winch project. “Instead, we’re scaling down to the Warn 1500AC, which is an off-the-shelf, consumable part, and when it dies, we can replace it.”
The team has made no major modifications to the 1500AC, other than replacing its 3/16-inch steel cable with a 3/16-inch synthetic rope.
“We’re trying to move away from steel cable,” Holman said, explaining that when a steel cable pulls something and snaps, energy stored inside the cable releases and creates a dangerous whipping action.
“When synthetic rope breaks, all the fibers just snap back in line. It doesn’t have the same whipping motion, so it’ll be a huge benefit in safety for the guys in the fleet,” he said.
The synthetic rope also proved stronger in testing, breaking at about 6,000 pounds, whereas the steel cable broke at 5,500 pounds.
Though synthetic rope comes standard on many newer commercial winches, Holman said, to his knowledge, this is the first time a military winch will use anything other than steel cable. Accordingly, the cargo team is working on a standard that will inform Marines of the characteristics of synthetic rope and how to inspect it.
“It’s always been steel cable for everything, so there’s actually no military standard for synthetic,” Holman said. “That’s how new this concept is for military applications.”
Meant to be mounted on vehicles or trailers, the 1500AC operates at a standard 60 hertz. Aircraft operate at a much higher 400 hertz, so the winch will be delivered to the fleet as part of a kit that will include a frequency converter and power distribution unit, which will plug into the aircraft’s utility receptacle and power the entire unit.
The three components will be mounted onto a plate that can be moved around the aircraft and secured using standard cargo straps. A fabrication shop at Naval Air Station (NAS) Patuxent River, Maryland, will manufacture the plates.
At 44 pounds, the relatively light kit can be moved around the cabin, giving Marines much more flexibility when loading cargo, Holman said. Currently, if Marines need to winch something into an aircraft that’s already loaded with cargo, they use snatch block pulleys to wrap the winch line around any obstructions. But with the Warn winch, Marines can move and secure the plate in front of any existing cargo.
“The concept behind the plate is giving the fleet flexibility with where they can position the winch. It’s only ever been a centerline, floor-mounted winch,” Holman said.
In addition, the move to an electric winch has allowed for removal of the hydraulic lines that were going to power the original winch, reducing the CH-53K’s weight.
The Aircraft Prototype Systems Division at NAS Patuxent River made three kits for qualification testing over the summer, which will determine how often the winch might need to be replaced over the life of the King Stallion. Whatever the results of that testing, Holman said he was confident it will prove to be far more cost effective than the current winch design.
The cargo team’s initial estimate is that the Warn winch will need to be replaced every 100 cycles at max load. Since the original winch was supposed to last 1,000 cycles—a requirement meant to last the life of the aircraft—Holman figures each Warn winch would ultimately need to be replaced 10 times.
“That’s just for the winch itself, which is the cheapest part of the whole assembly,” said Tim Reese, the CH-53K program’s deputy integrated product team lead for mission systems, landing gear and airframes.
Plus, not everything winched into an aircraft constitutes a max load, Holman noted.
“The estimates that we provide to the program office are going to be very conservative, assuming that every time I pull something into the aircraft, I’m maximizing the capability of this winch, which is not going to happen,” he said. “But that’s the current estimate—that I can make this winch last at least 100 cycles.”
Another four prototypes will be made for initial operational test and evaluation next year, after qualification testing is complete, Holman said.
‘I promise you it’s going to work’
The idea for a scaled-down winch originated in 2014 with the cargo team’s initial demonstration of the V-22 Osprey as an option for at-sea delivery of an F-35 Lightning II engine’s power module. During the demonstration, the team used a handheld winch called the PullzAll, another Warn product, to pull a representative skid into a V-22.
“We had one in the front and one in the back, and we maintained positive control over the module as it was coming inside the aircraft, and that’s what started everything,” Holman said. “We wondered, ‘Why can’t we just use these in the 53K?’”
But with a capacity of 1,000 pounds and line that only extends 15 feet, the battery-operated PullzAll didn’t pass muster as a fully capable cargo winch. Nonetheless, CH-53K squadrons will receive them in addition to the Warn 1500AC kits, giving fleet Marines a winch to use when the aircraft is shut down.
“Those will be handy if the fleet has to go somewhere; after they land and shut down the aircraft, they can use those without having to start up the auxiliary power unit,” Reese said. He estimated each CH-53K squadron will receive about 20 of the 1500AC kits and 10 PullzAlls.
After zeroing in on the Warn 1500AC, Holman and Montalvo visited Marine Aviation Weapons and Tactics Squadron (MAWTS) 1 in Yuma, Arizona, to get fleet feedback. They were able to secure time on a CH-53E, and a group of Marines gathered to watch them load various pieces of ground support equipment.
Holman recalled a crew chief’s doubts that a winch capable of pulling 1,500 pounds could move a 7,000-pound hydraulic cart, the heaviest piece of equipment at the demonstration. But Holman was unfazed.
“I said, ‘I promise you it’s going to work,’ and I showed him the math,” he said.
The winch pulled in the cart without difficulty, stunning the crew chief.
“The misconception is that the weight of the cargo or vehicle equates to the amount of load being put into the rope, and that’s not the case,” Holman said. “A line pull of 1,500 pounds equates to pulling a vehicle between 4,000 and 5,000 pounds up an 18.5-degree ramp. And once you use a snatch block and effectively double the winch’s strength, now you can pull a 10,000-pound vehicle up that ramp.”
Noting that the CH-53K is restricted to 10,000 pounds of internal cargo, the Warn 1500AC winch—with the help of a pulley—will be able to pull in anything that can physically be transported inside a King Stallion, said Mike Jackson, a mechanical engineer with the cargo team.
Holman said some Marines have voiced concerns the Warn 1500AC spools in more slowly than the winches currently on the CH-53E and MV-22B, but ultimately they prefer the new winch for its relative simplicity. The current winches “have a lot of intricate, little micro switches that you have to adjust for the winch to work, or even spool out and back in,” which can make them frustrating for fleet Marines to operate, Reese said.
“The line speed of the 1500AC is slower than the previous winch, but it gives the fleet a lightweight, mobile solution that can be used to support the mission at hand, and at the end of the day, it’s a better option than pushing cargo in yourself,” Holman said.
In some cases, slower might even be better. Jackson said the winch would end up having a “big impact” in the V-22 community, which has expressed interest in the winch project to load tactical vehicles by driving them in, only to have the tires slip on the loading ramp and hit the longerons.
“It’s going to be a training and paradigm shift,” Jackson said. “It’s going to take more time, but it’s usually not a fast effort when you’re winching something. It’s not going to slow down your day that much. Take the extra two minutes, and you’ll be fine.”
Jeff Newman is a staff writer and contributing editor for Naval Aviation News.