Is Defiant X likely to replace the Black Hawk? 

Defiant X is an upgraded version of Lockheed Martin’s SB-1 Defiant demonstrator (Sikorsky is owned by Lockheed Martin Corporation). The modified aircraft has the same surname as little brother Raider X, which is Lockheed’s submission for the Army’s other helicopter competition – the Future Attack Reconnaissance Aircraft (FARA) program. Both aircraft are built off Sikorsky’s X2 demonstrator first flew in 2008. 

Source: Lockheed Martin

The SB-1 was submitted for the FLRAA in 2021 which seeks to find a replacement for the Black Hawk utility helicopters that have been serving the US army since 1979.

The Sikorsky UH-60 Black Hawk has a cruise speed of 277km/h – 149 knots. There are more than two dozen variants of the Black Hawk, and this iconic war machine has served the military during the Gulf War, Panama invasion, and during operations in Afghanistan and Iraq. 

More than 4,000 Black Hawk helicopters have been built to date, and this American-made air assault aircraft has also been used by forces from several other countries, including Israel, Sweden, and Australia. Many military veterans believe that Black Hawk is the greatest utility aircraft ever built and it won’t be an easy task to replace this glorious war machine. 

However, for future missions, the US army is in want of a vertical takeoff and landing (VTOL) aircraft that is capable of flying at speeds of 230 knots (426km/h) or more. The Black Hawk is likely to remain in service for some time, but for missions in 2030 and beyond, the US army needs a better, faster, and much more advanced flying unit. 

 

The SB-1 Defiant achieved an impressive speed of 232 knots (429.7km/h) in a flight conducted in October 2020 and it is projected to cross 250 knots (463km/h) in upcoming test flights. The helo is powered by Sikorsky X2 technology, and uses two sets of coaxial propellers which stabilises the aircraft while leaving the tail section open for other uses. It also includes a push propeller, giving it a second source of thrust.

'Defiant X is purpose-built for a modernised Army that requires expanded reach, survivability, and lethality.' Steve Parker, vice-president and Boeing Vertical Lift

As far as the carrying capacity is concerned, Defiant X is able to carry up to 12 troops or a cargo weight of 1,670kg internally. A recent demonstration by Sikorsky revealed their prototype Defiant aircraft easily lift a training load of 2,400kg externally.

This carrying capacity suggests that the helicopter is well-equipped to move an infantry squad vehicle (ISV) or a heavy rocket-launching unit. In fact, Lockheed and Boeing claim that Defiant X is the only offering that can sling-load equipment during missions “at an operationally relevant distance.”

An image on Lockheed Martin’s website also shows Defiant X carrying an underslung M777-towed howitzer, a military ordnance which weighs about 94,218kg, which is just out of the Black Hawk's sling load capability of 4,082kg. However, the maximum external capacity of Defiant X is yet to be officially disclosed by the company.

Defiant X will also come with “fly-by-wire flight controls integrated with autonomy capability" that will make the Defiant X more agile and able to perform military operations such as flying low across forests and uneven terrain, including over the megacities, which the army believes may well become the battlefields of the future.

The aircraft is also said to have a thermal signature reducing feature that can keep it off enemy infrared sensors and reduce its vulnerability to shoulder-fired, infrared-guided missiles.

Defiant X vs V-280 Valor

The V-280 Valor aircraft from Bell. Source: Bell

In the coming years, the helo market is expected to be worth about $90 billion, and every big player in the market, whether it is Lockheed Martin or Bell Textron wants to grab the maximum share.

Defiant X, which is being hailed by Sikorsky and Boeing as the world's most advanced vertical lift weapon system is not alone in the race to win the FLRAA competition. It is in a neck-to-neck competition with Bell’s V-280 Valor, another advanced utility aircraft that is touted by its manufacturers as an unmatched alternative to Black Hawk.  

The V-280 is a tilt-rotor craft, similar to the V-22 Osprey, but smaller. Rather than relying on a large main rotor to provide lift in forward flight and for VTOL flying, it has two large tilt-rotors (called prop-rotors) at each of its wingtips, which can be positioned 90 degrees from horizontal to vertical. This means it flies like an airplane when in forward flight, and like a twin-rotor helicopter when in VTOL flight. 

 

Reports suggest that in tests, V-280 has flown at a speed of 300 knots (555.6km/hr) which is more than Defiant X currently manages. Moreover, with its two cargo hooks, Valor can move with an external load of 4,500kg, and internally the helicopter can easily carry 12 troops. 

Compared to Defiant X, Bell claims that the design of their aircraft offers extra safety to the pilot and those on the ground nearby, for example, the plane does not have a tail rotor that can pose risks to people on the ground and during a crash.

The Valor is also designed so that in the event of sustaining battle damage, some of its structures break away without threatening its passengers or crew with shrapnel. If one engine fails, the remaining engine can still send power to both proprotors, allowing it to do a short rolling takeoff in an emergency.

 

Surprisingly, the first flight of V-280 was conducted almost four years ago, on December 18, 2017. And, since then, Bell has continued to develop the aircraft to meet and exceed the FLRAA standards. However, the debut of SB-1 Defiant, and the Defiant X has certainly made this competition much more interesting for many defence experts and war veterans. 

Both Lockheed Martin and Bell Textron have made impressive claims about the range, agility, and manoeuverability of their helicopters, but the final test results are yet to come (most likely in 2022).

Some interesting details about Defiant X

Source: Lockheed Martin

Defiant X is an intelligently designed war machine that features a fly-by-wire control system, an electronic dashboard made to replace the manual aircraft control units, but this is not the only surprise you are likely to see in this future-ready helo:

• Defiant X may achieve a speed of 295.45 knots (547km/h) and this is possible because the dual coaxial propellers that are installed on the top also leave additional space for a third propeller. This extra push propeller can provide the aircraft more thrust and speed when required. 
• Sikorsky claims that their X2 technology will allow pilots to fly Defiant X at high speeds easily with low-speed handling qualities. This would enable the army to damage enemy units with minimum exposure, thus further enhancing the success rates and survivability of pilots. 
• In traditional helicopters, if the cables, cords, and pulleys are damaged during a mission then the pilot loses control over the aircraft, but with the new fly-by-wire technology there is no need for these physical control units. The pilot’s physical movements are turned into electrical signals which the flight computer translates into commands to the flight control surfaces. Both the Valor and the Defiant offer sophisticated fly-by-wire systems.

At present, more than 90% of rotorcraft (aircraft with rotary wings) serving the US Army have been manufactured by Sikorsky and Boeing, and Defiant X stands as perhaps the best utility aircraft they have made to date. But the road to an FLRAA contract is not an easy one. So will Defiant X become the new favorite American helo after Black Hawk? Only time will tell.