CH-53K King Stallions to hop across U.S. as testing continues

By Dan Parsons | August 4, 2021

Two of the U.S. Marine Corps’ new Sikorsky CH-53K King Stallion helicopters are set to cross from the Atlantic coast to the Pacific Ocean supported by aerial refueling tankers as they continue initial testing of the heavy-lift aircraft. 

The pair of 53Ks will depart Marine Corps Air Station New River, North Carolina, next week and, in two separate legs, fly to the Marine Corps Air-Ground Combat Center in Twentynine Palms, California. 

Along the way, the aircraft will demonstrate and gather data on the 53K’s ability to self-deploy by taking on gas mid-air from several pre-staged KC-130 aerial refueling tankers. So far, Marine Corps test pilots have completed aerial refueling while hauling external 27,000-pound (12,250-kilogram) loads during the day and with night vision goggles in the dark. Now they will validate that capability “at the operational level,” said Marine Corps Col. Jack Perrin, program director for CH-53 helicopters. 

Initial operational test and evaluation of the aircraft began in July in North Carolina and should continue through January or February 2022, Perrin said.

Aerial refueling, which has been validated in East Coast testing, will allow the 53K “not only to forward deploy, but also to do that long-range mission where it can take that heavy external load and take it out beyond 110 nautical miles because it can get gas along the way from behind a C-130.”

“That allows the Marine Corps to have a virtually unlimited logistics footprint because we can get there and support those troops, wherever they are, vertically,” Perrin told reporters Aug. 3 at the Navy League’s annual Sea-Air-Space conference outside Washington, D.C.

During testing in North Carolina, Marine Operational Test and Evaluation Squadron One (VMX-1) has already put its aircraft through more than 250 flight hours, Perrin said. Some of the four engineering and manufacturing development aircraft have undergone aerial refueling and other testing over the Chesapeake Bay from Naval Air Station Patuxent River in Maryland. Another fully instrumented aircraft is undergoing live fire testing to validate its ability to sustain battle damage and keep flying missions, Perrin said. 

In California, VMX-1 will begin putting the aircraft through its paces in mountainous and desert terrain. During desert flying, the test pilots will test the King Stallion’s fly-by-wire flight controls and hover-hold modes in dusty, brownout conditions, Perrin said. Marines have previously validated the aircraft performance in brownout conditions at Yuma Proving Ground in Arizona. Now they will try the 53K’s ability to perform dusty landings in an operational context. 

Landing in a degraded visual environments like brownout conditions “is the biggest threat to any rotary-wing aircraft because the pilots get disoriented; because you can’t see when you are down trying to land the aircraft, trying to pick up an external load.”

“The fly-by-wire system has taken that to the next level, where the aircraft is so stable . . . you can put it into a hover mode so it maintains that position exactly where you want it so you can hover over that load, or position yourself over the load, pick up that load and then depart in a degraded visual environment,” Perrin said. 

“We already have an envelope larger than the 53E and the H-60 on the LHD ship,” Perrin said. “On that big-deck ship, that amphib that we’re going to be operating from as a Marine unit, that aircraft can land and operate from that ship very well.” 

Five lots of 33 total aircraft are on contract with Sikorsky, which is owned by Lockheed Martin. Lot 6, funded in fiscal 2022, will bring the number on order to 42 aircraft. Seven of those aircraft are in various stages of assembly at Sikorsky facilities in Connecticut, according to Bill Falk, the company’s 53K program director.

Four King Stallions are on the final assembly line at the Stratford, Connecticut, facility where Sikorsky builds the H-60 Black Hawk. Two others are eight miles away in Bridgeport, where the airframes receive some modifications before loading onto the four-position final-assembly line in Stratford.

The first low-rate initial production aircraft has completed final assembly and is undergoing hangar operations to fill and test its fuel tanks and attach the main and tail rotor blades before beginning ground runs and initial flight testing prior to delivery, Falk said. 

“We plan on delivering that aircraft later this year,” he noted. 

A decision whether to enter full-rate production is due in fiscal year 2023, which begins Oct. 1, 2022. The first scheduled operational deployment is scheduled for late 2024 or early 2025 with full operational capability where the Marine Corps is flying only the 53K in 2029, Perrin said. 

Sikorsky already is planning for production to ramp up when the Marine Corps enters full-rate and then international customers join the program, Falk said. Where the company is now tooled to deliver one aircraft every three months, plans are to deliver two per month or 24 per year at full-rate production. Sikorsky is evicting the Black Hawk line that currently runs parallel to 53K production in Stratford and will double capacity to accommodate full-rate production, said Falk. 

“When we stack international on top of that, we will be building out capacity in the factory to delivery three aircraft a month, for a maximum capacity of 36 a year,” he added.