The US Marine Corps (USMC) has conducted a test flight of its second CH-53K helicopter, as part of its CH-53K King Stallion heavy lift helicopter programme.
The first and second CH-53K heavy lift helicopters have so far achieved more than 35 flight hours in total, including multiple flights with an active-duty USMC pilot at the controls.
These two flying CH-53K helicopters will be joined by two additional aircraft to complete flight qualifications of the USMC's next-generation heavy lift capability over a three-year flight test programme.
Developed by Sikorsky, the first two aircraft are the most heavily instrumented of the engineering development models (EDM), and will focus on structural flight loads and envelope expansion.
The additional EDM aircraft to join the flight line later this year would focus on performance, propulsion and avionics flight qualification.
Sikorsky CH-53K programmes vice-president Mike Torok said: "Adding a second aircraft into flight status signifies another milestone for the CH-53K programme.
"With both aircraft in flight test, our flight envelope expansion efforts will accelerate as we continue to make good progress toward our initial operational test assessment and 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.
According to Sikorsky, it will more than triple the payload to 27,000lb, over 110nm under 'high hot' ambient conditions.
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 USMC plans to stand up eight active duty squadrons, one training squadron, and one reserve squadron to support operational requirements.
Image: The second CH-53K aircraft achieves its first flight at Sikorsky's development flight test centre in West Palm Beach, Florida.