From early challenges to full-rate production: the journey of the Marine Corps’ most powerful heavy-lift helicopter
Early Development Challenges
The initial operational capability (IOC) date of the CH-53K faced delays, as a report from the office of the Director, Operational Test, and Evaluation (DOT&E) revealed. Early testing uncovered multiple design deficiencies that required correction. Testers discovered airspeed indication anomalies, low reliability of the main rotor gearbox, hot gas impingement on aircraft structures, structural problems with the tail boom and tail rotor, and overheating of the main rotor dampers.
As a result, the Initial Operational Test and Evaluation (IOT&E) was pushed back to early 2021 from its originally planned 2019 date. The first of about 200 CH-53Ks the Marine Corps was buying from Sikorsky under a $25 billion contract was delivered in May 2018 to Air Station New River in North Carolina, where it underwent further testing.
Bill Falk, Sikorsky CH-53K Program Director, stated that many items were already resolved by the time of the report’s publication. “We remain aligned on a program plan with Naval Air Systems Command and the USMC to support the first CH-53K deployment in 2023-2024,” he noted.
Flight testing continued with four engineering and manufacturing development (EMD) aircraft, three system development test articles, and a ground test vehicle. Those seven flyable aircraft had flown a total of 1,212 hours as of September 2018. Live fire testing showed the King Stallion was more resistant to small arms, automatic weapons, and man-portable air-defense systems than the CH-53E it would replace.
Successful Air Refueling Demonstration
The CH-53K King Stallion completed its maiden air-to-air refueling test in April 2020, demonstrating long-range logistics support capabilities. The 4.5-hour test was accomplished over the Chesapeake Bay with a KC-130J aerial refueling tanker.
“The aircraft went to the tanker this week and it was very successful, proving it is a long-range vertical logistic workhorse,” said Col. Jack Perrin, H-53 heavy lift helicopters (PMA-261) program manager, in a NAVAIR News Release.
The wake survey test assessed the aircraft’s performance when flying behind the tanker in strong, turbulent air. The crew successfully plugged the drogue, a funnel-shaped basket towed behind the KC-130J. These tests were performed at increasing closure rates to ensure the CH-53K could handle the forces on the refueling probe when contacting the drogue during aerial refueling.
“The successful air-to-air refueling test reinforces the superior capabilities of the CH-53K heavy lift helicopter and its ability to carry more Marines, cargo, and equipment over longer ranges and in more challenging environments than any other rotorcraft in the world. As the only fully marinized heavy lift helicopter, it will allow the Marines the operational flexibility and reach to fly over open waters to complete long-range missions in support of expeditionary advanced base operations,” Bill Falk noted.
First Fleet Mission: Mountain Recovery Operation
The CH-53K King Stallion performed its first operational fleet mission in September 2021 by successfully recovering a Navy MH-60S Knighthawk helicopter from Mount Hogue in the White Mountains of California. The two-day operation marked a significant milestone for the Marine Corps’ new heavy lift capability, which was amid Initial Operational Test and Evaluation with Marine Operational Test and Evaluation Squadron One (VMX-1) at Marine Corps Air Ground Combat Center Twentynine Palms, California.
“VMX-1 received a request for assistance from the Naval Safety Center about an MH-60S Knighthawk that suffered a hard landing near Mt. Hogue, Ca., at an elevation of 12,000′ Mean Sea Level (MSL) in July,” said Lt. Col. Luke Frank, CH-53K Detachment Officer in Charge for VMX-1, in a Navair news release.
The MH-60S Knighthawk was sitting on a high-altitude ridge in very rugged terrain near the California-Nevada line following a hard landing on July 16 during a search and rescue effort for a lost hiker. All four crewmembers survived without injury and were rescued the following day.
Both the MH-60S unit and the Naval Safety Center had exhausted all other resources for recovery, including the Army National Guard, the Navy, and the Marine Corps fleet squadrons. “They all lacked the capability to lift the aircraft without an extensive disassembly,” Frank explained.
After two weeks of exhaustive planning and assembling a team of more than 25 Marines and sailors from VMX-1 and 1st Landing Support Battalion from Camp Pendleton, California, the team deployed two CH-53Ks to Bishop, California. The MH-60S weighed approximately 15,200 lbs. and was positioned in a tight ravine at nearly 12,000′ MSL, requiring transport over 23 nautical miles to Bishop, California airport.
“After six months of flight operations with the CH-53K, the detachment had every confidence in the aircraft’s abilities to conduct the mission safely. Our main concern was the environmental factors ground support personnel would have to endure,” said Frank.
“This type of mission is precisely what the K was designed and built to do,” said Col. Kate Fleeger, program manager for the Heavy Lift Helicopter Program Office (PMA-261). “It continues to prove its value in support of Marine Corps operations, transporting equipment that no other rotary wing platform can lift.”
F-35C External Load Certification Test
In December 2022, a CH-53K King Stallion from Marine Operational Test and Evaluation Squadron (VMX) performed an external load certification lift of an inoperable F-35 Lightning II airframe at Naval Air Station (NAS) Patuxent River, Maryland. According to a NAVAIR News Release, the lift was conducted to evaluate the load and inform future lift capabilities.
The aircraft lifted was a developmental test carrier variant F-35C fighter jet that had accrued 750 flight hours during 450 test flights between 2010 and 2016. The structure was from the first F-35C carrier variant aircraft, CF-1, a former developmental flight test jet from the Patuxent River F-35 Integrated Test Force (ITF). the removal of its mission and propulsion systems, outer wings, and additional equipment.
The NAS Patuxent River F-35 ITF test team, Naval Air Warfare Center Aircraft Division (NAWCAD) Cargo Lab, and others ensured a successful lift and flight by conducting load certification testing, sling configuration analysis, and cargo characteristics documentation. Data from the tests informed the flight envelope for future events. An earlier crane test lift verified the sling, rig, pitch, and bank attitudes of the jet and control surface states.
ITF test teams collaborated with Marine Operational Test and Evaluation Squadron One (VMX-1) and a Marine helicopter support team with Combat Logistics Battalion (CLB) 24, Combat Logistics Regiment 2, 2nd Marine Logistics Group to conduct the lift. The CLB-24 helicopter support team conducted operations to develop tactics, techniques, and procedures of CH-53K King Stallion utilization as the Marine Corps modernized and prepared to respond globally to emerging crises or contingencies.
At the time, the CH-53K was cleared to conduct a 27,000-pound external lift and was projected to be cleared for a 36,000-pound external lift, nearly three times more under high, hot conditions than its predecessor, the CH-53E.
The recent full-rate production decision for the CH-53K validated the aircraft’s value to the USMC, and the test lift was one more demonstration of its performance and reliability.
The NAS Patuxent River F-35 ITF test team, Naval Air Warfare Center Aircraft Division (NAWCAD) Cargo Lab, and others ensured a successful lift and flight by conducting load certification testing, sling configuration analysis, and cargo characteristics documentation. Data from the tests informed the flight envelope for future events. An earlier crane test lift verified the sling, rig, pitch, and bank attitudes of the jet, and control surface states.
ITF test teams collaborated with Marine Operational Test and Evaluation Squadron One (VMX-1) and a Marine helicopter support team with Combat Logistics Battalion (CLB) 24, Combat Logistics Regiment 2, 2nd Marine Logistics Group to conduct the lift. The CLB-24 helicopter support team conducted operations to develop tactics, techniques, and procedures of CH-53K King Stallion utilization as the Marine Corps modernizes and prepares to respond globally to emerging crises or contingencies.
At the time, the CH-53K was cleared to conduct a 27,000-pound external lift and was projected to be cleared for a 36,000-pound external lift, nearly three times more under high, hot conditions than its predecessor, the CH-53E.
Full-Rate Production Approval
The CH-53K King Stallion entered Full Rate Production (FRP) and its deployment phase in December 2022, following a decision review by Frederick J. Stefany, Acting Assistant Secretary of the Navy for Research, Development, and Acquisition.
FRP occurred at the end of Low Rate Initial Production following a review assessing the results of Initial Operational Test and Evaluation (IOT&E), Live Fire Test and Evaluation, production readiness reviews, risk, and affordability analyses. On December 21, 2022, the Acquisition Decision Memorandum was signed, authorizing entry of the CH-53K into FRP.
FRP was an important milestone for the H-53 Heavy Lift Program Office (PMA-261), as it allowed the program to proceed beyond LRIP and begin increasing procurement quantities, thereby gaining production efficiencies and reducing unit costs.
“We have successfully demonstrated the performance and reliability of this aircraft,” said Col. Kate Fleeger, PMA-261 program manager, in a NAVAIR news release. “With FRP, we will continue to build on the strong manufacturing, sustainment, and support that has been established for the CH-53K.”
The US Marine Corps (USMC) continues to execute its transition from the CH-53E to the CH-53K and is on schedule to declare Full Operational Capability in FY2029.
Aircraft Capabilities and Specifications
The CH-53K is the USMC heavy lift replacement for the CH-53E. As the most powerful helicopter in the Department of Defense, the CH-53K is a new-build helicopter that expands the fleet’s ability to move more material, more rapidly throughout the area of responsibility, using proven and mature technologies.
Designed to lift 27,000 lbs/12,247 kg at a mission radius of 110 nautical miles (203 km) in Navy high/hot environments, the CH-53K is capable of lifting almost triple the baseline CH-53E lift capability. This increased payload capability can take the form of a variety of relevant payloads ranging from an internally loaded High Mobility Multipurpose Wheeled Vehicle (HMMWV) or the European Fennek armored personnel carrier and up to three independent external loads at once, providing incredible mission flexibility and system efficiency.
The helicopter features state-of-the-art, fly-by-wire technology that reduces pilot workload, contributes to aircraft stability, and improves overall safety. It is also designed to have a smaller shipboard footprint, lower operating costs per aircraft, and fewer direct maintenance man-hours per flight hour compared to its predecessor.
The CH-53K King Stallion advances Sikorsky’s 50 years of manufacturing and operational success with its CH-53A, CH-53D/G, and CH-53E predecessors. The helicopter has been designed and built to the exacting standards of the USMC and serves as its critical land and sea-based logistics connector. The new heavy lifter allows the USMC and international militaries to move troops and equipment from ship to shore and to higher altitude terrain, more quickly and effectively than ever before.
PMA-261 manages the cradle-to-grave procurement, development, support, fielding, and disposal of the entire family of H-53 heavy-lift helicopters. The USMC’s procurement objective is 200 helicopters.
Photos by U.S. Marine Corps / U.S. Navy
