The US Marine Corps' (USMC) CH-53K King Stallion heavy lift helicopter has completed its first external lift flight.
During the flight test, which was conducted at Sikorsky's Development Flight Test Center in West Palm Beach, Florida, US, the helicopter successfully carried a 12,000lb external load.
The first two of the CH-53K heavy lift helicopters completed their maiden flight last year and at the beginning of this year, respectively.
The helicopters have to date completed more than 50 flight hours, with one flight achieving a speed of over 140k.
The third and fourth King Stallion aircraft are slated to join the flight test programme this year.
During the course of the flight test programme, both of the current flying aircraft will be assessed in expanding the external load envelope.
Initial external payloads weighing 12,000lb will be flown first while hovering, and later at increased speeds to up to 120k. The aircraft will then carry 20,000lb and 27,000lb external payloads.
Sikorsky CH-53K programmes vice-president Mike Torok said: "Achieving our first external lift signifies another milestone for the CH-53K programme.
"Our flight envelope expansion efforts remain on track, and we continue to make good progress toward our initial operational test assessment later this year, and ultimately full aircraft system qualification."
The CH-53K King Stallion features similar physical dimensions and a reduced footprint compared to its predecessor, the three-engine CH-53E Super Stallion helicopter.
This helicopter comes with a modern glass cockpit, fly-by-wire flight controls, fourth-generation rotor blades with anhedral tips, a low maintenance elastomeric rotor head, and upgraded engines.
Sikorsky's CH-53K also features the US Air Force pallet compatible cargo rail system; external cargo handling improvements; survivability enhancements; and improved reliability, maintainability and supportability.
The US Department of Defense's Programme of Record currently has 200 CH-53K aircraft, while the USMC is planning to field eight active duty squadrons, one training squadron, and one reserve squadron to support operational requirements.
Image: The CH-53K King Stallion helicopter achieves its first flight with an external load at Sikorsky's Development Flight Test Center in West Palm Beach, Florida, US. Photo: courtesy of PRNewsFoto/Lockheed Martin.