The CH-53K King Stallion helicopter successfully completed a 27,000 pound payload external lift test, prime contractor Lockheed Martin [LMT] said Thursday.

Sikorsky, a Lockheed Martin company, is developing the King Stallion heavy lift helicopter for the Marine Corps.

A Sikorsky CH-53K King Stallion heavy lift helicopter completes a  a 27,000 pound payload external lift test. Photo: Lockheed Martin.
A Sikorsky CH-53K King Stallion heavy lift helicopter completes a a 27,000 pound payload external lift test. Photo: Lockheed Martin.

This was an “out of ground effects” (OGE) external load test at 100 feet above the ground while performing hover maneuvers to demonstrate control authority in the flight regime, Lockheed Martin said. The test occurred at Sikorsky’s Development Flight Test Center in West Palm Beach, Fla.

An OGE load is the most stressful helicopter lift condition from a power requirement standpoint, the company said. It is defined as an altitude greater than the helicopter’s main rotor diameter where power demand greatly increases due to loss of the benefit of ground effect. The King Stallion’s rotor diameter is 79 feet.

“This 27,000 pound external lift is yet another key milestone for the program. The King Stallion achieved this external lift with ease, and we are on track to successfully complete the initial operational assessment this year,” Michael Torok, Sikorsky vice president for CH-53K programs, said in a statement.

The CH-53K previously achieved speeds over 140 knots. The first two produced King Stallions verified capabilities in excess of predecessor CH-53E with a third unit having recently joined the flight test program. A fourth rotorcraft is in final preparation for flight status and is expected to join the flight test program later this summer.

“Lifting 27,000 pounds in OGE conditions is another key milestone for the program, which further confirms our confidence in the design and performance of the aircraft,” Col. Hank Vanderborght,  Marine Corps program manager for the Naval Air Systems Command’s (NAVAIR) Heavy Lift Helicopters Program, added.

Vanderborght said this was the most strenuous performance demonstration test before achieving Milestone C and entering production.

The CH-53K is planned to carry a 27,000 pound external load for up to 110 nautical miles at 91.5 degrees at altitudes up to 3,000 feet, which are operational requirements for Navy “high hot” conditions. The King Stallion is expected to have over triple the payload of its predecessor CH-53E to accommodate sizes including an internally loaded High Mobility Multipurpose Wheeled Vehicle (Humvee).

The Defense Department’s Program of Record calls for 200 CH-53K helicopters with the first four scheduled for delivery in 2017 to the Marine Corps. Four additional aircraft are under long-lead procurement for parts and materials with delivery scheduled fort 2019. The initial operating capability with the Marine Corps is expected in 2019, Lockheed Martin said.

The service intends to stand up eight active duty CH-53K squadrons, one training squadron, and one reserve squadron to support operational requirements.