SURVIVING

Survivability was a concern when designing the UH-60 in the early 1970s, and it’s a challenge that’s only gotten tougher. Whichever FLRAA contender is selected, it will have to survive at the ‘X’ – defined by the army as the terminal area where it needs to go to deliver troops, conduct reconnaissance, or pull off attack missions.

The Valor is designed to sustain battle damage with structures that break away without threatening its passengers or crew. If one engine fails, the remaining functional engine can still send power to both proprotors. According to Bell, it cannot hold a hover with one engine out, but it could do a short rolling take-off in an emergency. Bell’s emphasis is on speed, not traditional helicopter strengths, such as hovering, with the V-280.

‘I think the hot LZ scenario is more survivable in a tiltrotor than in typical helicopters. You’re really minimising that time of vulnerability,’ McGuinness says. ‘There’s nothing that I’d do in a [Black Hawk] that I wouldn’t do in this aircraft. I have no trouble taking this plane to the X.’

Conversely, Sikorsky-Boeing has emphasised rotary-wing capabilities. With its pusher-propeller disengaged, the SB-1 is essentially a conventional twin-engine helicopter, its coaxial main rotors notwithstanding. Like Bell, SikorskyBoeing considers the last five kilometres travelled to the LZ the most vulnerable for an assault aircraft.

Randy Rotte, Boeing’s sales director for Future Vertical Lift, explains that the Sikorsky-Boeing team didn’t want to sacrifice helicopter qualities to get speed and endurance. If Defiant loses an engine, for example, it can still hover reliably and fly at up to 150 knots.

‘If we lose one engine or the [pusher-prop], we are still able to complete the mission,’ Rotte says.