WASHINGTON — The build of the Bell Helicopter V-280 Valor tilt-rotor demonstrator aircraft is 100 percent complete, the company announced Wednesday, and the aircraft is about to begin ground runs in advance of a first flight.

The U.S. Army has been planning — through its Joint Multi-Role demonstrator program — for two very different vertical lift prototypes to begin flight demonstrations this fall as part of a critical path to informing and shaping the design of a Future Vertical Lift helicopter fleet expected to hit the skies in the 2030s.

Bell Helicopter is “within days” of beginning restrained ground runs at its Amarillo Assembly Center in Texas, said Keith Flail, the company’s vice president of advanced tilt-rotor systems, who spoke to Defense News at the Association of the United States Army’s aviation symposium Thursday.

While he was hesitant to pinpoint a date when the helicopter will rise off the ground for its very first flight, Flail said the event would take place well within the year.

Following a series of restrained ground runs, the company will move to unrestrained ground runs. And when everything is determined ready to go, Bell will fly the helicopter for the first time, which will likely be nothing more than what is typical for a first flight — a low hover over the ground.

More significant testing will follow over the course of a year as the Army observes the potential capability.

The other prototype’s first flight has fallen behind the originally intended goal of September. The Sikorsky-Boeing-made SB-1 Defiant coaxial helicopter is now expected to start flying some time in the first half of 2018.

The aircraft is based off of Sikorsky’s patented X2 technology, which is also being used in the company’s internally developed helicopter, Raider, which experienced a hard landing earlier this summer.

State of unmanned: Bell Helicopter offers update on the V-247 Vigilant

As services look to multimission capabilities for unmanned platforms, Bell Helicopter hopes to fill a Marine Corps gap with the V-247, said Keith Flail, vice president of advanced tiltrotor systems.