Bell has achieved Level 1 handling qualities with the V-280 Valor, demonstrating that the advanced tiltrotor has low-speed agility that matches or betters that of the Sikorsky UH-60 Black Hawk helicopter.
Demonstrating that a tiltrotor could have the affordability and low-speed maneuverability to perform the UH-60’s utility mission is key to unlocking the potential to replace the U.S. Army’s Black Hawk fleet with a rotorcraft that has twice the speed and twice the range.
The fly-by-wire V-280 has logged 110 flight hours since its first flight in December 2017 under the Army’s Joint Multi Role Technology Demonstration (JMR TD), the precursor to the Future Long-Range Assault Aircraft program to replace the UH-60.
Bell has now collected data that shows the tiltrotor has the attitude quickness required for Level 1 flying qualities under ADS-33 handling requirements for rotorcraft, says Ryan Ehinger, V-280 program manager. Attitude quickness is the rate at which the aircraft responds in pitch, roll and yaw.
“The engineering data shows what we predicted based on the fidelity of our models,” he says. Bell is focused on demonstrating Level 1 agility “at the X”—in the landing zone—where the V-280’s handling qualities “are as good as, and in some cases better than, the H-60’s,” he says.
Level 1 agility was one of the key performance parameters (KPP) “baked into” the V-280’s design from the outset, says Ehinger, with the proprotors having greater blade-flapping capability compared with the V-22 Osprey’s to provide increased control power at low speed in rotorborne flight.
The V-280 already has demonstrated Bell’s speed KPP, meeting its cruise target of 280 kt. at 10,000 ft, and has exceeded 300 kt. at that altitude in testing. The aircraft also has achieved a mission radius of 259 nm at 220 kt., exceeding its KPP target of 229 nm, and flown at up to 14,200 ft. density altitude.
Climb rate so far is up to 4,500 ft./min, which is “significant versus traditional helicopters,” says Paul Wilson, V-280 chief engineer, speaking at the Vertical Flight Society’s Forum 75 convention in Philadelphia May 16.
The Army plans to extend flight testing of the V-280, and rival Sikorsky/Boeing SB-1 Defiant coaxial rigid-rotor compound helicopter, beyond scheduled completion of the JMR TD at the end of fiscal year 2019. Bell’s goals for the additional flying include achieving autonomous operation by year’s end, Ehinger says.