DEFIANT VS VALOR

INSIDE THE HEAD-TO-HEAD BATTLE TO REPLACE THE BLACK HAWK

- ERIC TEGLER

In 2022, the US Army will choose a new aircraft to replace the Sikorsky UH-60 Black Hawk helicopter. Bell’s V-280 Valor and Sikorsky-Boeing’s SB-1 Defiant will battle it out to become the winner of the Future Long-Range Assault Aircraft (FLRAA) programme, and either the Valor or the Defiant will fly as the army’s next combat helo when it deploys in 2030.

But ‘helicopter’ isn’t even the right word to describe these two aerial beasts.

Bell’s V-280 Valor is a tilt-rotor, similar to the V-22 Osprey currently flown by the US Marine Corps, Air Force, and Navy, but smaller and with a V-tail. Rather than relying on a single large main rotor for lift in forward flight and vertical take-off and landing (VTOL) like a helicopter, it tilts two large rotors (called proprotors), one at each of its wing tips, 90° from horizontal to vertical and back. It’s essentially an aeroplane in forward flight and a twin-rotor helicopter in VTOL flight.

Meanwhile, Sikorsky-Boeing’s SB-1 Defiant is a compound helicopter, with stacked, counter-rotating main rotors, a pusher-propeller, and aircraft-like rudders. The pusher-propeller can provide significant forward thrust, relieving the need to tilt its main rotor for forward flight. Counter-rotating main rotors provide extra lift, stability, and smoothness. They also give the SB-1 speed, climb, and VTOL advantages over normal helicopters.

Both designs stem from the US Army’s desire for a multimission VTOL aircraft that flies much faster and further than the workhorse Black Hawk. The army wants its UH-60 replacement to be capable of a top speed of 230 knots (425 km/h) – a twin-engine Black Hawk tops out at 159 knots (295 km/h).