Future Vertical Lift: Difference between revisions

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The Future Vertical Lift (FVL) is a program to develop a family of helicopters for the United States Armed Forces. Variants of four different sizes will be developed sequentially. They will share common hardware such as sensors, avionics, engines, and countermeasures.^[1] The U.S. Army has been considering the program since 2004. It was planned to be a technology demonstration program as of October 2010.^[2][3] The program is meant to develop a replacement for the Army's UH-60 Black Hawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa.^[4][5] The precursor for FVL is the Joint Multi-Role (JMR) helicopter program, which will provide technology demonstrations.^[6]

Design requirements

In March 2013, the Army asked industry to submit proposals for an effort called the Alternative Engine Conceptual Design and Analysis. Although formal requirements for the FVL family of systems have not yet been set, they will need to have hover, speed, range, payload and fuel efficiency characteristics "beyond any current rotorcraft". This may require an aircraft that can hover at 10,000 ft and cruise at 30,000 ft. The engine will require alternative, advanced engine/power system configurations that enable enhanced mission capability, such as improved time on station, increased mission radius, and quieter operation. Due to the different configurations of the airframe, power outputs from 40 shp to 10,000 shp are being studied. The engine design should be ready by the start of the demonstration phase of the FVL program in 2017. One to four companies can be awarded a contract with work completed in 18 months.^[7]

Competitors

• Sikorsky Aircraft and Boeing are jointly producing a medium-lift-sized demonstrator for phase one of the program. It will fly in 2017 and will be evaluated by the Army for further development.^[8][9] Sikorsky is leading the development of phase one with an aircraft based on their previous Sikorsky X2 design. Compared to conventional helicopters, the counter-rotating coaxial main rotors and pusher propeller offer a 185 km/h (115 mph) speed increase, combat radius extended by 60%, and performs 50% better in high-hot hover performance. Boeing plans to lead phase two, which is the mission systems demonstrator phase.^[10]

• Bell Helicopter is pitching a third-generation tiltrotor design for the FVL program. Bell is seeking partners for financial and technological support, although the company does not require the assistance.^[11] In April 2013, Bell revealed its tiltrotor design, named the Bell V-280 Valor. It is designed to have a cruise speed of 280 knots (320 mph; 520 km/h), range of 2,100 nautical miles (2,400 mi; 3,900 km), and a combat range of 500 to 800 nmi (580 to 920 mi; 930 to 1,480 km). It features a V-tail, a large cell carbon core wing with a composite fuselage, triple redundant fly-by-wire flight control system, retractable landing gear, and two 6-foot (1.8 m) wide side doors for ease of access. The V-280 is unique in that the rotor system tilts, but not the engines themselves. The planned demonstrator is medium-sized and carries 4 crew and 11 troops.^[12][13]

• AVX Aircraft is proposing an aircraft with their coaxial rotor and twin ducted fan design that provides better steering and some additional forward power.^[14] It is capable of flying at 230 kn (260 mph; 430 km/h), with 40% lift from the fans and 60% from the rotors. Half the drag of the design comes from the fuselage and half from the rotor system, so wind tunnel tests are aiming to reduce drag by a third. The rotor system has two composite-flexbeam hubs with drag-reducing aerodynamic fairings on the blade cuffs and the mast between the hubs.^[15] The medium sized version is proposed to weight 27,000 lb (12,000 kg), carry 4 crew and 12 troops, and have a 13,000 lb (5,900 kg) external lifting capacity.^[6]

• EADS is submitting an unknown proposal, but is expected to have one based on the Eurocopter X3.^[14]

• Piasecki Aircraft is bidding its PA61-4 Advanced Winged Compound (AWC). The full-compound version can fly at 233 kn (268 mph; 432 km/h) and uses their vectored-thrust ducted propeller (VTDP), flown previously on the Piasecki X-49. It propels the aircraft and has a long-span wing for lift and anti-torque. The wing pivots in pitch for addition flight control and to reduce rotor download in the hover. Removing the wing but retaining the VTDP produces the 180 kn (210 mph; 330 km/h) thrust compound version, which can be used for shipboard operations. Replacing the VTDP with a conventional tail rotor produces the 160 kn (180 mph; 300 km/h) version, which is slower but is lighter, cheaper, and can better handle external-lift or vertical-replenishment missions.^[15]

Configurations

Four size configurations are envisioned:^[16]

• JMR-Light: Scout version to replace the OH-58 Kiowa; introduction planned for 2030.
• JMR-Medium: Utility and attack version 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.
• 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 - are being studied.^[17]

References

External links

• Modernizing the Army’s Rotary-Wing Aviation Fleet, Chapter 2 "Approaches to Modernizing the Fleet". Congressional Budget Office, November 2007.