iCorrection - This story has been updated to reflect accurate maximum speed achieved by the V-280 Valor to date.
WASHINGTON — The two vertical lift aircraft under development for the U.S. Army are making headway on the road to one day delivering a potential future medium-lift aircraft to the joint force.
A Sikorsky and Boeing team and Bell have been independently building two very different Future Vertical Lift aircraft as part of the Joint Multi-Role Technology Demonstrator effort that kicked off several years ago. The demonstration will inform requirements for the Army’s FVL family of systems that will come online in the 2030s.
Bell has now been flying its V-280 Valor tiltrotor aircraft for the better part of a year, while Sikorsky-Boeing’s SB-1 Defiant coaxial helicopter will fly — if all goes well — by the end of the year.
Sikorsky and Boeing have been building up to a potential first flight by refining technology in wind tunnel testing, a software integration lab, a power-train system test bed and through the building of its first demonstrator aircraft, according to Rich Koucheravy, Sikorsky’s business development director for FVL.
The team has some testing to wrap up in the wind tunnel in October and will continue to run flight algorithms through its software integration lab, he said.
The power-train systems test bed in West Palm Beach, Florida, which essentially is identical to the Defiant aircraft except its fuselage is an iron frame strapped to the ground, is about to have rotor blades installed and will begin full-up testing as a system with the blades soon, Koucheravy said.
The aircraft that will fly is completely built, Koucheravy said, and awaits rotor blade installation. The rotor blades are complete and will be shipped to the aircraft in West Palm Beach within the next few weeks, he added.
The test bed will begin running as a full system this month, and Defiant will begin ground runs in November in preparation for a first flight.
Barring any unforeseen “stubbery” in the test bed or during ground runs, the aircraft will fly by the end of the year, according to Koucheravy.
Defiant experienced delays in the development program due to transmission issues and challenges in developing the tooling for building the rotor blades.
“Those challenges are behind us,” said Randy Rotte, Boeing’s director of cargo helicopter and FVL programs.
Now, the conduit through which the team has to go through to get to flight “is all about the [test bed],” Rotte said.
All of the various components of the aircraft have been tested individually, but now they will come together in the test bed, and the team will see how they all perform together as a system, he explained.
“This is invention,” Rotte said.
Defiant is a brand new helicopter, not just a new configuration of something. It does, however, use X2 coaxial technology from Sikorsky development programs like the S-97 Raider, which is flying now in Florida, through internal investment.
“We will have some unexpected discoveries,” as the test bed runs and the aircraft goes through ground runs, Rotte said.
How quickly the team can move to get Defiant into the air will depend on what issues arise, he said.
The team does not want to rush to fly by the end of the year if something is discovered that needs additional examination and development work, Rotte and Koucheravy said.
Meanwhile, the V-280 Valor left its nest at Bell’s flight test center in Amarillo,Texas, for the first time since it became airborne and has relocated to the company’s Arlington, Texas, facility, according to Jeff Schloesser, Bell’s executive vice president for strategic pursuits.
The company did a dry run of the trip on Sept. 17 around the Amarillo area, flying the aircraft for just over two hours and traveling a total of 370 miles.
On Sept. 18, Valor flew to Arlington, logging 360 miles in less than a few hours with “very little in the way of maintenance in between,” Schloesser said.
Now that the aircraft is at the flight research center in Arlington, it will be able to perform more advanced flight tests.
Valor, so far, has achieved 250 knots true air speed, adjusted to compensate for altitude and temperature, and has flown at 11,500 feet.
The aircraft has achieved a 4,500 feet per minute rate of climb at 160 knots, which Schloesser said is “unheard of in most vertical lift flight.” It represents three to five times as fast of a vertical climb as legacy aircraft are capable, including the UH-60 Black Hawk utility helicopter, which will eventually be replaced by the FVL family of aircraft.