Future Vertical Lift

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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.

Overview

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. FVL is being pursued by the U.S. Army and the U.S. Special Operations Command. The U.S. Marine Corps plans to continue using its current fleet "for the foreseeable future" due to budget plans and with roles filled by helicopters with their required shipboard amphibious capability.

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. 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.

Configurations

Four size configurations are envisioned:

• 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.
• 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.

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.

Competitors

External images
Drawing of SB>1 Defiant
Full-size mock-up of Bell V-280 Valor

• 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. 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. The Boeing-Sikorsky team is seen to have an advantage, given their industrial base, the fact that their helicopter designs are the most used in the Army, and because the Army has had little interest in tiltrotor technology, like that submitted by Bell. The design will have a cruise speed of 230 kn (260 mph; 430 km/h). Sikorsky has said that the X2 design is not suitable for heavy-lift size, and instead suggests the CH-53K for heavy-lift and tiltrotor for the ultra-class. At Association of the U.S. Army 2013, Sikorsky and Boeing announced that their X2-based rotorcraft for the JMR-TD program was named Defiant, and that the team and aircraft will be separate from the S-97 Raider.

• Bell Helicopter is pitching a third-generation tiltrotor design for the FVL program. Bell sought partners for financial and technological support, although the company did not require assistance. 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.

• AVX Aircraft is proposing an aircraft with their coaxial rotor and twin ducted fan design that provides better steering and some additional forward power. 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. 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. It has a six-by-six foot cabin, which is twice the interior of the UH-60 Black Hawk, and has an 8,000 lb (3,600 kg) internal lifting capacity. The aircraft can carry 12 NATO litters, have an auxiliary fuel system for self-deployment over distances, and is planned to be capable of being optionally manned. The utility and attack versions will have 90% commonality and fly at the same speed. Test aircraft will be equipped with current GE T706 engines, but AVX is looking to equip their design with the Advanced Affordable Turbine Engine with its higher 4,800 hp output. AVX has teamed with Rockwell Collins, General Electric, and BAE Systems. It features entry doors on both sides of the fuselage with a large rear ramp for easy cargo handling. Both versions have retractable landing gear, and the attack variant carries all armaments stored inside until needed to provide a clean aerodynamic design.

• Karem Aircraft will design an optimum-speed tiltrotor (OSTR), designated the TR36TD demonstrator. It will have twin 36 ft (11 m)-diameter variable-speed rotors powered by existing turboshaft engines. The production version of the TR36D would have a level flight speed of 360 kn (410 mph; 670 km/h). Karem says its variable-speed OSTR configuration offers advantages in weight, drive train, and aerodynamic and propulsive efficiency. It has high speed, “robust” hover performance at altitude, higher climb rate and sustained maneuverability, and longer range than other vertical-takeoff-and-landing configurations. They also say it offers reduced complexity, inherent safety advantages, simplified maintenance, and low total ownership cost.

Former entries

• EADS was planning to submit a proposal for the JMR Phase I demonstration, expected to have been based on the Eurocopter X3, but withdrew in late May 2013 to focus on its bids for the Armed Aerial Scout program. The company also said the cost of developing a high-speed rotorcraft was greater than the funding that would have been awarded. The EADS proposal was not totally based on the X3 design, but did leverage aspects of its technology. EADS may re-submit its proposal for FVL when the Army creates specific requirements.

• Piasecki Aircraft was bidding its PA61-4 Advanced Winged Compound (AWC). The full-compound version was planned to fly at 233 kn (268 mph; 432 km/h) and used their vectored-thrust ducted propeller (VTDP), flown previously on the Piasecki X-49. It propelled the aircraft and had a long-span wing for lift and anti-torque. The wing pivoted in pitch for addition flight control and to reduce rotor download in the hover. Removing the wing but retaining the VTDP produced the 180 kn (210 mph; 330 km/h) thrust compound version, which could be used for shipboard operations. Replacing the VTDP with a conventional tail rotor produced the 160 kn (180 mph; 300 km/h) version, which was slower but was lighter, cheaper, and could better handle external-lift or vertical-replenishment missions. The Piasecki entry was not selected for the Joint Multi-Role phase of the program.

Development

Joint Multi-Role

On 5 June 2013, Bell announced that its V-280 Valor design had been selected by the Army for the Joint Multi-Role (JMR) Technology Demonstrator (TD) phase. The Army classified the offering as a Category I proposal, meaning it is a well-conceived, scientifically or technically sound proposal pertinent to program goals and objectives with applicability to Army mission needs, offered by a responsible contractor with the competent scientific and technical staff supporting resources required to achieve results. The Boeing-Sikorsky team, pitching the high-speed compound helicopter design based on the X2 prototype, also reported they were invited to negotiate a technology investment agreement for the JMR-TD Phase I program. JMR-TD contracts were expected to be awarded in September 2013, with flights scheduled for 2017. AVX Aircraft also confirmed that it had been selected for the JMR Phase I as a Category I participant. Their entry is a coaxial-rotor compound helicopter with ducted fans for propulsion and small wings to offload the rotors at high speed. The company plans to build a 70% scale demonstrator using existing General Electric T700 engines. EADS withdrew from the program before designs had been selected, and Piasecki Aircraft was not chosen to continue in the effort. On 31 July 2013, Boeing and Sikorsky pledged they will invest more than double the amount money the government is spending on JMR if the team is chosen to build and demonstrate a rotorcraft for the program. On 6 August 2013, Lockheed Martin said it will offer a new mission equipment package to meet the requirements for the JMR/FVL program. Lockheed will incorporate future airborne capability environment software standards into the aircraft's cockpit and mission systems to use their avionics, sensors, and weapons. Boeing and other companies are expected to offer rival sets of avionics. On 9 September 2013, Bell announced Lockheed would be teaming with them on the V-280.

On 2 October 2013, the U.S. Army awarded technology investment agreements to AVX Aircraft, Bell Helicopters, Karem Aircraft, and Sikorsky Aircraft under the Joint Multi-Role Technology Demonstrator Phase I program. There are two general types of proposals: tiltrotors with rotors that serve as both rotors and conventional propellers, and gyrocopter-like aircraft with immobile vertical rotors and separate rear-mounted propellers. AVX and Sikorsky are offering gyrocopter designs with two counter-rotating rotors to provide vertical lift. For forward movement, AVX uses two ducted fans and Sikorsky uses a single propeller on the back. Bell is offering the V-280 Valor tiltrotor. Karem Aircraft is offering a tiltrotor with optimum-speed rotors, allowing the aircraft to speed or slow the propellers depending on speed or efficiency demands. Similar technology was used on the A160 Hummingbird. JMR-TD is not to develop a prototype for the next family of vehicles or pre-select an airframe for FVL, but to develop and demonstrate an operationally representative mix of capabilities, technologies, and interfaces to investigate realistic design trades and enabling technologies. The TIAs give the four teams nine months to complete preliminary design of their rotorcraft, which the Army will then review and authorize the construction of two competing demonstrators to fly in 2017. While there was a potential for an early downselect, the four teams are focused on the 2017 flight demonstrations. Emerging results from JMR TD Phase 1 will be used to inform the FVL effort regarding vehicle configurations, the maturity of enabling technologies, attainable performance and capabilities, and will highlight affordable technical solutions required to achieve those capabilities. On 21 October 2013, defense executives bidding for the program confirmed that the Army will downselect two companies in 2014, who will them develop prototypes for flight tests in 2017. JMR-TD phase I is focused on creating a medium utility rotorcraft airframe, while phase II will develop mission systems and software.

External links

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