King Stallion Summer: CH-53K to enter operational test in July

By Dan Parsons | April 23, 2021

Estimated reading time 13 minutes, 50 seconds.

A fleet of four CH-53K King Stallions this summer will begin the final leg of testing for the U.S. Marine Corps’ new heavy-lift helicopter ahead of its entry to service in 2023, but work remains to ensure that milestone doesn’t slip to the following year. 

The Marine Corps is in the final throes of wringing out its several engineering and manufacturing developmental 53K models ahead of initial operational test and evaluation (IOT&E) with aircraft representative of what Marines will fly. Marines now have their hands on three production aircraft and are training to fly and maintain them at Marine Corps Air Station New River in North Carolina. 

Marines watch a CH-53K King Stallion prepare to land at Marines Corps Outlying Field (MCOLF) Camp Davis, North Carolina, March 17, 2021. U.S. Marine Corps photo by Lance Cpl. Yuritzy Gomez.
Marines watch a CH-53K King Stallion prepare to land at Marines Corps Outlying Field (MCOLF) Camp Davis, North Carolina, March 17, 2021. U.S. Marine Corps Photo by Lance Cpl. Yuritzy Gomez

“I’m expecting that in the July timeframe that that’s going to happen,” H-53 helicopters program manager Col. Jack Perrin told Vertical in a recent interview. “It all depends on how the training goes and how the aircraft act.”

A fourth aircraft is scheduled to join them to form a cadre of four 53Ks assigned to the VMX-1 operational test squadron around the end of July, Perrin said. 

Commandant of the Marine Corps Gen. David H. Berger took a spin in one of the King Stallions at New River on March 17.

“The aircraft is performing wonderfully,” Perrin said in March, when there was a single aircraft at New River being used to train pilots and maintainers ahead of IOT&E. “We’ve actually flown . . . over 50 hours of total training time on that aircraft. The pilots love it. The maintainers love it. They are really doing great things.”

Training of pilots and maintainers is progressing quickly with the aircraft — two more “system demonstration test articles” arrived in early April — and simulators available for both skill sets, Perrin said. The aircraft have been available for flight when needed, having made all planned launches on time, he said. 

A CH-53K King Stallion prepares to land at Marines Corps Outlying Field (MCOLF) Camp Davis, North Carolina, March 17, 2021. U.S. Marine Corps photo by Lance Cpl. Yuritzy Gomez.
A CH-53K King Stallion prepares to land at Marines Corps Outlying Field (MCOLF) Camp Davis, North Carolina, March 17, 2021. U.S. Marine Corps Photo by Lance Cpl. Yuritzy Gomez

“What’s great about it is the aircraft and the simulator fly exactly the same, which is a hard thing to do and some platforms it’s close but it’s not quite the same as it is with the 53K,” he said. “They’ve done a lot of work in the simulator so that’s allowing them to really go and get a lot of great work done in a short period of time.” 

Through major gear box problems, engine exhaust reingestion troubles and other developmental delays that some have blamed on the service’s hard drive to field the behemoth new helicopter, the Marine Corps has remained unflinchingly optimistic about the King Stallion’s value. While the legacy CH-53E Super Stallion continues to pull its weight, those decades-old airframes are in need of replacement to support expeditionary Marine Corps operations, service aviation leaders insist. 

Sikorsky, which is owned by Lockheed Martin, is now on contract for four lots of aircraft totaling 24 CH-53K King Stallions, which will replace the Marine Corps’ CH-53E as the primary heavy lift utility helicopter and ship-to-shore troop transport.

Most recently, in October 2020, the Marine Corps agreed to pay $550 million for six King Stallions to be delivered in early 2024.

“We’re in the process of negotiating that contract right now to get those aircraft in the hopper, if you will and in production so we can get those delivered to the fleet and start building up the fleet,” Perrin said.

Sikorsky CH-53K King Stallion. Lockheed Martin Photo
Sikorsky CH-53K King Stallions in flight. Lockheed Martin Photo

Perrin said the aircraft is “on track and executing” to formally enter service and deploy in fall of 2023 or spring of 2024, but the hits have not subsided. Two recent government-required reports on the program’s progress highlighted ongoing issues with the aircraft failing to meet reliability targets. 

A Government Accountability Office (GAO) report on 53K development published March 4 found a “moderate risk of not demonstrating the required levels of reliability or payload carrying weight by the end of operational testing.” GAO also found that concurrency, coupled with plans for increased numbers of helicopters to be produced, beyond the six per year currently being built, could result in costly retrofits to helicopters built before the completion of operational testing. 

“We continue to work with our customer on an integrated test plan,” said Sikorsky CH-53K program director Bill Falk. “The team is already addressing technical issues cited in the report, a majority of which have been resolved, and are confident we have solutions to address the few outstanding issues to enter into IOT&E as scheduled this year.”

For his part, Perrin was able to put those findings in context of an aircraft that, in its relative infancy with about 3,000 total flight hours, has not proven how it will fare under hard use. He disagreed with the assertion that the Marine Corps should keep to buying just six aircraft a year.

“We do have some more developmental testing to go, but what I would tell you is that from my seat, what I see in my day-to-day action, is the aircraft is performing really well,” Perrin said. “I completely agree there is risk. Until it’s proven, there’s always risk. However, I think our projections and the engineers that look at that and pore through all the data . . . it’s really shown that will do well and I’m excited to see how it is when it is at that 60,000-hour mature level.” 

“I think we are well poised to continue to build up, to continue to ramp up so we can transition the Marine Corps in a smart manner from the 53E to the 53K,” he added. “We don’t believe that we should stay at six. We believe that we are in a position, with the testing we have done, that we should continue to expand and continue up the ramp as the Marine Corps and Congress see fit to appropriate funding.”

Sikorsky’s Falk said the company is “proceeding to deliver those aircraft” toward the service’s stated requirement for 200 aircraft. 

Sikorsky has six aircraft on the line at Sikorsky facilities in Connecticut and more than 30 in various stages of production, according to Falk. Sikorsky and its suppliers have made significant investments in facilities, machinery, tooling, and workforce training to ramp up production required for the CH-53K program.

“We are negotiating with the U.S. Navy on our next contract proposal for additional technologically-advanced CH-53K heavy lift helicopters to support the high-end maritime fight,” Falk said. “We prioritize affordability and our proposal delivers substantial lot over lot price reduction.”

First on the list of operational test points could pose a challenge: flying in the sandy desert around Marine Corps Air Ground Combat Center Twentynine Palms in California. 

The U.S. Director of Operational Test and Evaluation’s 2020 report on major military weapon system development highlighted a seemingly alarming tidbit about the CH-53K’s three 7,500-shaft-horsepower T408-GE-400 engines. In brownout conditions at Yuma Proving Ground in Arizona, the engines showed considerable wear-and-tear from particle ingestion and would therefore require an inordinate amount of maintenance and/or replacement when flying in dusty environments. 

CH-53K helicopter landing in brownout
The CH-53K conducts a reduced visibility landing at Yuma Proving Ground in Arizona. Lockheed Martin Photo

“Engine performance degradation in brownout conditions will necessitate extremely frequent engine replacements and repair if the Marine Corps continues to train and operate in locations where brownout conditions are prevalent. CH-53K aircrew cannot realistically perform external cargo delivery operations within the 70-second operating limit.”

Perrin said the conditions at Yuma not only are designed specifically as worst-case dust-storm landing zones, but that heavy-lift helicopters rarely if ever operate from unprepared areas where prolonged engine ingestion would be an issue. At sometimes 116 degrees Fahrenheit (46 Celsius), the fine Arizona sand melted when ingested into the engine, then cooled and solidified inside the cooler stages of the turbine engine, as expected, Perrin said. 

A “tiger team” similar to the one that solved previous exhaust reingestion issues has been established with members from Sikorsky, General Electric and the Marine Corps to study the engine’s problems with brownout conditions. 

“I believe that by the time we begin IOT&E we will have mitigated that so we will be able to do a full operational test and evaluation on the aircraft and I believe that when we go to deploy the aircraft, we will have been able to make changes either to the motor or to the aircraft that allows it to operate at longer times in those dusty environments. We still have work to do, but we’re going to continue to work on that,” Perrin said.

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