Sikorsky Aircraft has started bladed ground testing of the first S-97 Raider prototype helicopter, which is being offered for the US Army's armed aerial scout (AAS) programme.
Taking place at an undisclosed location, the ground phase will see the S-97 Raider team evaluate the first of two prototypes as a completed system for the first time.
The team will conduct initial ground tests with the aircraft tied down, focusing on verifying correct operation of the propulsion system and drive train, as well as the rotor control system and pilot-vehicle interface.
Sikorsky Aircraft S-97 Raider programme manager Mark Hammond said: "Testing all of the aircraft's systems together, for the first time, marks significant progress in the development of this next-generation helicopter and moves the programme closer to first flight."
Launched in October 2014, the first prototype has completed software qualification testing, as well as component fatigue and gearbox testing.
Under development since October 2010, the S-97 Raider is based on Sikorsky's rigid X2 rotor coaxial design and is designed to surpass legacy military helicopters in manoeuvrability, payload, speed, range and high / hot environmental conditions.
The armed reconnaissance rotorcraft features next-generation technologies in a multi-mission configuration, including armed aerial scout or light assault, and can carry six troops and external weapons.
The 100% industry-funded helicopter has coaxial counter-rotating main rotors and a pusher propeller that provide cruise speeds up to 220k, a composite airframe and a maximum gross weight of slightly more than 11,000lb.
In addition to ground tests, Sikorsky is preparing for the final assembly of the second prototype at its Development Flight Centre in West Palm Beach, Florida, US.
The company received the fuselage structure from Aurora Flight Sciences in last month.
Sikorsky Advanced Military Programmes director Steve Engebretson said: "We look forward to the opportunity to demonstrate the Raider's revolutionary performance and unmatched manoeuvrability for the US Army.
"We are delivering on our promise to design and build a helicopter with performance capabilities not seen before."
The AAS programme aims to replace the US Army's ageing fleet of OH-58D Kiowa Warrior multi-mission helicopters.
Image: The first S-97 Raider prototype will be evaluated as a completed system for the first time during the ground runs phase. Photo: courtesy of Sikorsky Aircraft Corporation.