Future Vertical Lift (FVL) is a program to develop a family of helicopters for the United States Armed Forces. Four different sizes of aircraft are to be developed. They are to share common hardware such as sensors, avionics, engines, and countermeasures. The U.S. Army has been considering the program since 2004. FVL is meant to develop a replacement for the Army’s UH-60 Black Hawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa helicopters. The precursor for FVL is the Joint Multi-Role (JMR) helicopter program, which will provide technology demonstrations planned for 2017.
Summary
After a decade of combat from Operation Iraqi Freedom and Operation Enduring Freedom, the U.S. Department of Defense found that the U.S. Army’s rotorcraft fleet was wearing out. Combat operations made the helicopters fly five times more often than in peace time. Manufacturers have been remanufacturing and upgrading existing families of aircraft without creating original platforms. The Future Vertical Lift (FVL) concept is to create a new rotorcraft that uses new technology, materials, and designs that are quicker, have further range, better payload, are more reliable, easier to maintain and operate, have lower operating costs, and can reduce logistical footprints. FVL is to create a family of systems to replace most Army helicopters. The Joint Multi-Role (JMR) phases will provide technology demonstrations. JMR-TD will develop the aerial platform; JMR Phase I will develop the air vehicle; JMR Phase II will develop mission systems. The Army plans to acquire as many as 4,000 aircraft from the FVL program.
Future Vertical Lift was established in 2009 as an initiative, not yet a solution, by the Secretary of Defense to focus all DoD vertical lift capabilities and technology development, as well as retaining long-term engineering capabilities. In October 2011, the Deputy Secretary of Defense issued the FVL Strategic Plan to outline a joint approach for the next generation vertical lift aircraft for all military services. The Strategic Plan provided a foundation for replacing the current fleet with advanced capability by shaping the development of vertical lift aircraft for the next 25 to 40 years. It indicates that 80 percent of decision points for the DoD vertical lift fleet to either extend the life, retire, or replace with a new solution occurring in the next 8-10 years. Implementation of the FVL Strategic Plan which will impact vertical lift aviation operations for the next 50+ years. The U.S. Navy is a partner to the Army on the effort, so a derivative of FVL may be used in the Navy’s MH-XX program to replace the service’s MH-60S/R helicopters.
Configurations
Four size configurations (which may or may not be of the same design) are envisioned to replace 25 current rotorcraft types :
JMR-Light: Scout version to replace the OH-58 Kiowa; introduction planned for 2030.
JMR-Medium: Utility and attack versions to replace the UH-60 Black Hawk and AH-64 Apache; introduction planned for 2027-2028.
JMR-Heavy: Cargo version to replace the CH-47 Chinook; introduction planned for 2035, although Boeing expects 2060.
JMR-Ultra: New ultra-sized version for vertical lift aircraft with performance similar to fixed-wing tactical transport aircraft, such as the C-130J Super Hercules and the Airbus A400M Atlas; introduction planned for 2025.
According to the U.S. House Armed Services Committee, three different configurations of JMR aircraft – a conventional helicopter, a large-wing slowed rotor compound helicopter, and a tiltrotor – were being studied as of April 2013.
The challenge for the bidders in the ongoing JMR-TD competition is to design an aircraft for the FVL-Medium requirement that can be scaled up or down. The FVL-Medium must be sized to carry 14 troops, accelerate to 230kt (425km/h) and fly at least 2,100nm (3,890km) without refuelling.
October 2013, the army narrowed to four the bidding teams for JMR-TD, selecting two groups using a tiltrotor configuration and two using coaxial compound helicopters.
Of the latter, Sikorsky and Boeing have teamed up to offer the SB-1 Defiant, a follow-on to Sikorsky’s self-funded X-2 high-speed demonstrator and the ongoing S-97 Raider development project.
The SB-1 would feature the same coaxial and rigid rotor system to provide vertical lift and a pusher propeller to provide thrust. Boeing would integrate the Honeywell T55 engine that now powers the CH-47.
AVX, a company founded by former Bell chief engineer Troy Gaffey, is pairing a similar coaxial rotor system with dual ducted fans. The fans provide propulsion and differential thrust for yaw control, a classic problem for coaxial rotor systems, Gaffey says.
The airframe will consist of composite skins bonded to metal frames.
Gaffey is also proposing to use an innovative business model by teaming with a group of 15 or 16 small companies scattered across the USA to produce the aircraft. “We are trying to become a virtual aircraft OEM,” says Gaffey. “It could very well bring a different level of competitiveness going forward.” “One thing we learned about composites is if you mechanically fasten them the way aluminum is built, you end up with a very expensive carbonfibre structure,” he says.
In some ways, Bell Helicopter has already fielded an aircraft in the FVL-Medium class with the V-22 Osprey. However, it represents an older generation of design skills and technology and the efficiency of its rotor system is constrained by the US Marine Corps’ requirement to operate on amphibious carriers.
So Bell has teamed with Lockheed to develop the V-280 Valor, which it describes as a third-generation tiltrotor, with the experimental XV-15 representing the first generation. The “280” part of its designation represents the aircraft’s potential velocity in knots, slightly higher than the V-22’s listed maximum speed of 272-275kt.
Finally, Karem Aircraft has proposed an optimum- speed tiltrotor. Founder Abe Karem gained prominence by designing the Amber unmanned air system, which was renamed the Predator after it was acquired by General Atomics Aeronautical Systems. Karem then moved on to develop optimum-speed rotor technology. For the past decade, Karem has been adapting the geared rotor for commercial and military markets, with a 75-seat tiltrotor aircraft called the TR-75
Aerotrain. Karem adapted the TR-75 into a design called the TR-36 to meet the FVL-Medium requirements. The “36” in the designation refers to the size of the aircraft’s rotor diameter in feet.
