With Boeing revealing its offering for the U.S. Army Future Attack Reconnaissance Aircraft (FARA) prototype competition on March 3, all five proposals that will compete with each other are finally unveiled.
U.S. Army FARA Program
The FARA program was initiated by the U.S. Army in 2018 to develop a successor to the Bell OH-58 Kiowa armed scout helicopter as part of the larger Future Vertical Lift (FVL) program.
The OH-58 was retired in 2014; three prior programs for a successor were canceled prior to reaching production: Light Helicopter Experimental (1982–2004, resulting in the Boeing–Sikorsky RAH-66 Comanche), Armed Reconnaissance Helicopter (2004–06, resulting in the Bell ARH-70 Arapaho), and Armed Aerial Scout (2012–13, evaluating commercial off-the-shelf designs).
The FARA Competitive Prototype (FARA CP) program falls under U.S. Army Futures Command and the U.S. Army Combat Capabilities Development Command (CCDC) Aviation & Missile Center (AvMC)’s Aviation Development Directorate.
The mandatory requirements of the program included the integration of government-furnished equipment: engine, gun and rocket launcher, a minimum speed, specific target gross weight, a maximum 40-foot diameter rotor, and an affordability goal.
Range, endurance, and payload were among the desired requirements that provided industry trade space for their specific design. Apart from those mandates, the timing of the execution plan, funding profile requirements, acceptable risk level, statute requirements and the potential of executing the entire program all the way through field capability by 2028 were also examined.
Design contracts for FARA candidates were awarded to five manufacturers, out of eight proposals, in April 2019. They are AVX Aircraft (in partnership with L3Harris Technologies), Bell Helicopter, Boeing, Karem Aircraft, and Lockheed Martin’s Sikorsky Aircraft. Two of the manufacturers will be selected to proceed with their designs in 2020, and prototypes are scheduled to first fly in 2023. The production design is scheduled for selection in 2028, but may occur sooner.
The five contenders for the program are:
• Boeing’s FARA offering – Single main rotor with a pusher propeller and a conventional tail rotor; tandem-seat cockpit.
• Sikorsky RAIDER X – Compound coaxial helicopter with coaxial counter-rotating main rotors and a pusher propeller; side-by-side cockpit.
• Bell 360 Invictus– Conventional design with a single main rotor and a Fenestron (ducted tail rotor), with added wings to reduce rotor lift demand in forward flight; tandem-seat cockpit.
• Karem AR40 – Active-rotor, winged, compound helicopter design with a three-blade rigid main rotor and a swiveling tail rotor; side-by-side cockpit.
• AVX /L3 Compound Coaxial Helicopter (CCH) design – Compound coaxial helicopter with two ducted fans providing forward and reverse thrust, and wings to provide lift in forward flight; side-by-side cockpit.
A detailed look at the five competing designs:
Boeing’s FARA offering, revealed on March 3, is a thrust compounded single-main rotor helicopter which boasts a six-bladed rotor system, a single-engine, tandem seating and a modular, state-of-the-art cockpit with a reconfigurable large area display and autonomous capabilities.
The fly-by-wire (FBW) design leverages more than 65 years of rotorcraft experience, proven advanced and additive manufacturing technology, and product commonality driving down risk and costs. The system will provide seamless capability within the Army ecosystem to include Long-Range Precision Fires (LRPF) and air-launched effects (ALEs).
Sikorsky RAIDER X
Sikorsky, part of Lockheed Martin company, is offering the RAIDER X next-generation light attack/reconnaissance helicopter concept for the program. The helicopter was unveiled on Oct. 14, 2019.
The RAIDER X concept is an agile, lethal and survivable compound coaxial helicopter design based on Sikorsky’s X2 experimental high-speed compound helicopter.
The helicopter is a scaled-up version of the Sikorsky S-97 Raider helicopter, which was originally developed for the Army’s Armed Aerial Scout (AAS) program, and is also similar in configuration to the Sikorsky–Boeing SB>1 Defiant, developed jointly with Boeing. Boeing and Sikorsky are offering the larger SB-1 Defiant helicopter for the Army’s Future Long Range Assault Aircraft (FLRAA) program to replace UH-60 Black Hawk utility helicopters.
The S-97 features next-generation technologies that are expected to meet or exceed the Army’s FARA requirements. The coaxial counter-rotating main rotors and pusher propeller provide cruise speeds up to 220 knots (253 mph), significantly more than the speed of conventional helicopters. The clutched rear propeller can boost speed or shut off in hover. The Raider also exhibits enhanced maneuverability, significantly improved high/hot hover performance, and greater range and endurance.
The helicopter is powered by a single GE Aviation YT706 turboshaft engine, a 2,600 shaft-horsepower variant of the T700 engine hat includes a FADEC (full authority digital engine control).
Bell 360 Invictus
In October 2019, Bell Textron Inc. announced a new rotorcraft, Bell 360 Invictus, as the company’s entrant for the U.S. Army’s FARA Competitive Prototype program.
Bell’s offering has a typical helicopter configuration with a single main rotor and a Fenestron (ducted tail rotor). Invictus’ rotor system design is based on the rotor system of Bell 525 Relentless helicopter, which has been tested and proven at speeds in excess of 200 Knots True Air Speed (KTAS). The 360 Invictus has wings which will reduce rotor lift demand in forward flight, enabling high-speed maneuverability.
The helicopter’s main engine will be a single General Electric T901 turboshaft engine, with supplemental power from a Pratt & Whitney PW207D1 turboshaft engine.
Bell has announced a teaming agreement with Collins Aerospace Systems, a unit of United Technologies Corp. (UTC), for the FARA competitive prototype program. As the mission systems integrator, Collins Aerospace will deliver a new generation of avionics hardware and software featuring cyber-hardened and digital backbone solutions to the prototype.
According to the company, the Bell 360 Invictus meets or exceeds all requirements as laid out under the FARA contract.
Karem Aircraft unveiled its FARA proposal, the new AR40 compound helicopter design, at the AUSA 2019 Exposition. The AR40 is an active-rotor, winged, compound helicopter design with a three-blade rigid main rotor and a swiveling tail rotor.
The main rotor, with a diameter of 11 m, uses Karem’s Optimum Speed Rotor technology, where the speed of the rotor is adjusted between the vertical and horizontal phases of flight to maintain the optimum loading on the blades to maximize propulsive efficiency. The system also lets each of the three blades on the rotorcraft’s main rotor to be controlled individually, instead of forcing the blades to move in unison as is the case with a traditional swashplate system.
The tail rotor will be angled backwards in horizontal flight acting as a pusher propeller and, according to the company, the aircraft’s vertical stabilizer will compensate for torque from the main rotor. The aircraft also has a tilting wing with a wingspan of 12.2m. The wing can provide the majority of the aircraft’s lift while in horizontal flight. It will be tilted vertically during the ascent and descent for aerodynamic reasons.
The aircraft will be powered by a single GE Aviation T901 engine which was selected by the Army for its Improved Turbine Engine Program (ITEP). Karem claims that the AR40 will have a maximum speed of around 220kt.
The aircraft’s cockpit has side-by-side seating configuration. There is also a small cabin behind the cockpit that can accommodate four passengers, such as special operations forces.
Karem is partnering with Northrop Grumman and Raytheon on the AR40. Karem is contributing its rotor and drive technologies and is leading the design and prototyping process. Northrop is providing production and product support, as well as avionics expertise. Raytheon is the mission systems integrator and modular open systems architect.
AVX /L3 Compound Coaxial Helicopter (CCH)
The AVX Aircraft Company and L3 Technologies announced their FARA offering based on innovative compound coaxial helicopter (CCH) design in April 2019.
The design is a coaxial helicopter with two ducted fans providing forward and reverse thrust. The innovative design solution will exceed the reconnaissance and light-attack mission of FARA with a high-performing and survivable platform, according to the developers.
AVX-L3 CCH will meet 100 percent of mandatory requirements and exceed 70 percent of them. The CCH design, combined with rigorous engineering and production processes and certifications, will deliver a safe, performance-driven, affordable aircraft capable of operating in highly contested airspace and degraded environments for extended periods.