Futuristic Defiant impresses US Army brass

Jan 14, 2024

Many of us have seen the movie Black Hawk Down, where two UH-60 Black Hawk helicopters get their tail rotors shot off over Mogadishu, sending them careering into an enemy city that virtually comes down on them, with disastrous results.

As chopper pilots say, lose your tail rotor, lose everything.

If Sikorsky-Boeing's SB-1 Defiant happens to win the service's new Future Long Range Assault Aircraft (FLRAA) under the Future Vertical Lift (FVL) competition, that won't ever happen again.

Test pilots in West Palm Beach, Florida, say the futuristic dual-rotor helicopter could get its tail shot off in combat and still fly faster than an undamaged Black Hawk, Matthew Cox of Military.com reported.

That's because it has a big push prop on the end, instead of tail rotor … and, it's entirely electric.

The Sikorsky-Boeing Defiant, which just performed a high-profile flight demo for Army brass, strikes an intimidating silhouette with its prominent X2 technology, which features a coaxial rotor system and a large rear propeller that replaces the tail rotor found on conventional helicopters, the report said.

Sikorsky-Boeing officials said the new aircraft design will be capable of flying at speeds of more than 200 knots, or 230 mph, and maneuvering like a fine-tuned sports car, the report said.

Test pilots say they love the rear pusher-prop, which is designed to provide revolutionary thrust, but are also comforted that it can take direct hits, the report said.

"It's all self-contained back here; you can take significant combat damage back here, and if you lose the prop, you are still a 150-knot machine," Ed Henderscheid, former US Army AH-64 Apache pilot and Boeing's lead test pilot for Defiant, told reporters.

Unlike a conventional tail rotor, the rear pusher prop is completely electric, he said.

"Not having hydraulics in the tail boom as a helicopter pilot is a huge deal," Henderscheid said. "I have had hydraulics failures where they were caused by a break in the hydraulic line … and it's scary when you have to go to keep your tail rotor where you want it. Not having to worry about a leak … or some mechanical failure — that's a really, really comforting thought."

The Army awarded a team from Sikorsky, part of Lockheed Martin and Boeing, a contract to build Defiant as part of the Joint Multi-Role Technology Demonstrator program, the report said.

A Textron-Bell team also received a contract and built the V-280 Valor, a tiltrotor helicopter that completed its first test flight in December 2017, the report said.

The Defiant faces stiff competition from the Valor, which flew at 200 knots at a test flight in January, according to Defense News.

During Thursday's test demo, Defiant flew at about 140 knots, but only used about 20% of the pusher propeller capability and about 30% of the engine power, the report said.

The pusher prop can also be reversed very quickly to provide negative thrust for quick braking power, and then turned off for a quieter sound signature, said Bill Fell, a former Army aviator and senior experimental test pilot, the report said.

"Coming into that objective, I’m using all of the thrust from the prop. And when I am close enough where I want to lower acoustic signature because I don't want to let them know I am coming, I can disengage it and fly in at helicopter like speeds," Fell said.

This wasn't lost on former Army Black Hawk pilot Sen. Tammy Duckworth, D-Illinois, who attended the Defiant flight demo.

The former Army National Guard officer lost both of her legs after she was shot down by enemy fire in Iraq in 2004.

"The ability to slow down within a very short distance — within a half mile — to be able to go from 200 to zero — that's amazing," Duckworth said. "I think about the fact that when I was flying … I was slow, I was exposing my belly to everyone, to anyone who wanted to shoot at me.

"I got shot down flying 10 feet above the trees going 100 knots."