Behold Sikorsky’s “Raider X” Future High-Speed Armed Reconnaissance Helicopter

The Army wants a survivable and fast “knife fighter” helicopter to fight in contested areas. The Raider X certainly seems like it could be just that.

byTyler Rogoway|
Behold Sikorsky’s “Raider X” Future High-Speed Armed Reconnaissance Helicopter

Last week Bell unveiled its 360 Invictus high-speed armed scout helicopter contender for the Army's Future Armed Reconnaissance Aircraft (FARA) tender and now Sikorsky is firing back with its long-anticipated entrant, the "Raider X." The aircraft is based directly on its S-97 Raider demonstrator, which leverages the company's X2 compound helicopter technology to achieve very high speed and maneuverability for a rotorcraft. The company's larger SB>1 Defiant, which is taking part in the Joint Multi-Role (JMR) technology demonstration program now and is likely to try to capture the Future Vertical Lift-Medium contract in the future, also uses this unique configuration. Sikorsky's X2 technology has been developed and funded internally for over a decade. You can read all about it and the S-97 in this exclusive War Zone interview with the company's X2 team. 

The S-97 Raider demonstrator serves as a basis for the Raider X design, although with some significant differences. , Sikorsky

Bell is not Sikorsky's only competitor for the FARA contract, which is slated to fill the void that the prematurely retired OH-58D Kiowa Warrior left and also replace a number of AH-64 Apaches, in the decade to come. The company, which is now a subsidiary of Lockheed Martin, is also facing off against Boeing, AVX and L3, and a powerful consortium that includes Karem, Northrop Grumman, and Raytheon. Boeing and the latter team have yet to show off their FARA concepts. 

Sikorsky says that their Raider X is the leader in the "service’s revolutionary approach for rapid development and delivery of game-changing technology and warfighter capabilities, equipped for the most demanding and contested environments. Raider X enables the reach, protection, and lethality required to remain victorious in future conflicts." 

The company goes on to highlight the unique capabilities of the Raider X:

·       Exceptional Performance: The X2 rigid rotor provides increased performance including; highly responsive maneuverability, enhanced low-speed hover, off-axis hover, and level acceleration and braking. These attributes make us unbeatable at the X.

·       Agile, Digital Design: State-of-the-art digital design and manufacturing is already in use on other Lockheed Martin and Sikorsky production programs such as CH-53K, CH-148 and F-35, and will enable the Army to not only lower the acquisition cost, but enable rapid, affordable upgrades to stay ahead of the evolving threat.

·       Adaptability: Modern open systems architecture (MOSA)-based avionics and mission systems, offering “plug-and-play” options for computing, sensors, survivability and weapons, benefiting lethality and survivability, operational mission tailoring and competitive acquisitions.

·       Sustainable/Maintenance: Designed to decrease aircraft operating costs by utilizing new technologies to shift from routine maintenance and inspections to self-monitoring and condition-based maintenance, which will increase aircraft availability, reduce sustainment footprint forward and enable flexible maintenance operating periods.

·       Growth/Mission Flexibility: Focused on the future and ever evolving threat capabilities, X2 compound coaxial technology provides unmatched potential and growth margin for increased speed, combat radius and payload. This potential and growth margin further enables operational mission flexibility which includes a broader range of aircraft configurations and loadouts to accommodate specific mission requirements.

Sikorsky Raider demonstrator during flight testing., Sikorsky

Some other features of the X-2 technology in the raider were stated by the company as such:

With RAIDER X, Sikorsky introduces the latest design in its X2 family of aircraft. To date, X2 aircraft have achieved/demonstrated:

  • Speeds in excess of 250 knots
  • High altitude operations in excess of 9,000 feet
  • Low-speed and high-speed maneuver envelopes out to 60+ degrees angle of bank
  • ADS-33B (Aeronautical Design Standard) Level 1 handling qualities with multiple pilots
  • Flight controls optimization and vibration mitigation

Sikorsky experimental test pilot Bill Fell, who has taken the Raider on the majority of its test flights, also stated the following about the X2 technology: 

“The power of X2 is game changing. It combines the best elements of low-speed helicopter performance with the cruise performance of an airplane... Every flight we take in our S-97 RAIDER today reduces risk and optimizes our FARA prototype, RAIDER X.”

The concept image of the Raider X is very similar to the S-97, but with a number of significant refinements. It appears that some low-observable considerations may have been driving factors of its design. The rendering shows a helicopter that is free of radar-reflective components bolted on to the airframe, such as sensors, pylons, antennas, or weapons. In fact, it looks as if its 20mm cannon is concealed when not in use. Its rotor head shrouds are also angled and it has a v-shaped inlet design feeding a deeply buried gas turbine engine.

Its exhaust also appears to be buried inside its tail boom and it could even use a similar cooling system as found on the company's long-defunct RAH-66 Comanche. The protruding contour soffit on the tail would point to this feature. On the Comanche, the hot exhaust of the engine was mixed with cool air and vented through this area. 


In addition, the edges of its fuselage appear to also be chined, like the Comanche. In fact, the chine line is quite similar, albeit less extreme. The airframe also appears to be designed with continuously changing radiused surfaces. 

We must stress that these could also be features largely intended to make the airframe as efficient and the helicopter as fast as possible, and they may just appear to share some tenets of low-observable design. We have reached out to Sikorsky for clarification on this. 

Also remember that there are varying degrees of low-observability and reducing the aircraft's radar cross-section and infrared signature significantly, while not going nearly as far as the Comanche, would still be a major win in terms of survivability. This is especially true considering that this machine will also have speed, new situational awareness enhancing sensors, and advanced defensive countermeasures on its side when it comes to surviving over a modern battlefield. 

A similar design was teased for the FVL Light requirement that came before the FARA tender was formally announced. , Sikorsky/Lockheed Martin

The Raider X, with its coaxial compound configuration, will certainly be a top kinetic performer out of the FARA contestants, but even though Sikorsky really stresses that their X2 technology is low risk, that term is very certainly subjective. It is true that the company has spent over a decade developing the technology, but it has never been put into production and it is substantially higher-risk in nature than what Bell is offering, which is really a conventional helicopter. Considering its complexity, the Raider X could also come with a significantly higher price tag, although we really can't say that definitively at this time. Then again, is a low-cost, lower-performing option really even worthwhile persuing for the FARA mission at all? 

In a new era of advanced integrated air defense systems (IADS) networks and capable short-range air defense systems, it's already questionable that any traditional helicopter can persistent over highly contested territory and survive reliably in order to do it over and over again. Range is also an issue. In an age of anti-access, area-denial strategic realities, will the prospect of basing helicopter units within say 150 miles of an objective area even be realistically possible in any way? 

We will be talking more in-depth about these issues in the near future, but with them in mind, range, speed, and especially survivability should really be placed above everything else if the FARA concept is even worth investing billions into at all. Otherwise, it seems like something of a wasteful tribute to the days or rotary-wing warfare that seems to have already passed us by. 

The S-97's unique lines seen from above in this striking image., Sikorsky

The Raider X could very well deliver in the speed, range, and even in the survivability department if it is indeed stealthy in nature and has the latest defensive aids, sensors, and weaponry. If it doesn't, it will be a complex helicopter with some developmental risk that may come in at a significantly higher price than some of its competitors. But once again, even if something is cheaper, is it worth really doing it at all if it isn't survivable or even employable in a future higher-end conflict?

We'll have to wait to answer these questions as FARA progresses, but for now, we finally know exactly what Siksorsky's offering will look like, and it is quite impressive.


Sikorsky has posted a promotional video of the Raider X:

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