News

2020-07-07

Future Vertical Lift Modernising the U.S. Army

The U.S. Army is leading the biggest rotorcraft programme in the history of international air forces. The Future Vertical Lift (FVL) in an ambitious plan to replace all the U.S. Department of Defence’s (DoD) helicopters with next-generation rotorcraft.

Acting as both a combat multiplier and a lifeline in austere environments, helicopters and tilt-rotor aircraft greatly multiply the effectiveness of ground forces whether performing transport, logistics, strike or reconnaissance duties.

The FVL initiative came out of the increasing concerns of the Vertical Flight Society and its members that DoD had stopped making adequate investments in new rotorcraft programmes, when the former American Helicopter Society (AHS) noted that the DoD was too focused on upgrades and the modernisation of existing platforms.

Combat operations made helicopters fly five times more frequently than in peacetime but after a decade of combat, from Operation Iraqi freedom and Operation Enduring Freedom, the DoD found that the U.S. Army’s rotorcraft fleet was wearing out. Hundreds of helicopters and lives were lost in the Afghanistan and Iraq conflict, with huge gaps left between the legacy rotorcraft fleet’s capabilities and commanders’ needs for speed, range, altitude, automation, connectivity, reliability and maintainability.

The Chinook, Black Hawk, Apache and Kiowa Warrior are based on designs from the 1960s and 1970s but still remain major combat rotorcraft platforms in the U.S. inventory, with the V-22 being the only new U.S. military rotorcraft design fielded in the past 30 years. Now the U.S. Army is leading the DOD’s effort to move to a new generation of rotorcraft technology.

FVL Background and History

The Future Vertical Lift (FVL) programme is a research and development effort dedicated to discovering, investigating and refining the technologies providing the next generation of vertical lift aircraft for the United States Armed Forces. The U.S. Army lists FVL as one of its top six modernisation priorities, while the U.S. Marine Corps and Navy plan to use FVL-derived technology in their next-generation rotorcraft.

FVL officially began in 2009 with the project plan launched in October 2011, but the pace of work has varied due to shifting U.S. Army budget priorities. For years, the Army has been pursuing a technology maturation programme called the Joint Multi-Role Technology Demonstrator (JMR-TD) intended to demonstrate transformational vertical-lift capabilities.

JMR-D has prepared the DoD for replacing the current vertical-lift fleet while reducing risk to the FVL. Both efforts will play key roles in future DoD rotorcraft fleet development.

Five aircraft sizes will be developed, sharing common hardware such as sensors, avionics, engines and countermeasure. According to the Army, the programme’s goal is to develop technologies improving “manoeuvrability, range, speed, payload, survivability, reliability, and reduced logistical footprint.”

To improve on current rotorcraft, FVL is currently looking at five basic categories (or capability sets) of varying aircraft size:

JMR-Light: Scout version to replace the OH-58 Kiowa, with introduction planned for 2030. Implemented as the Future Attack Reconnaissance Aircraft (FARA) programme in 2018.

JMR-Medium-Light: U.S. Navy version to replace Seahawks/Fire Scouts with FVL Maritime Strike.

JMR-Medium: Utility and attack versions replacing the UH-60 Black Hawk and AH-64 Apache, with introduction planned for 2030. Implemented as the Future Long-Range Assault Aircraft (FLRAA) programme in 2019.

JMR-Heavy: Cargo version to replace the CH-47 Chinook, with introduction planned for 2035 although Boeing anticipates 2060 more realistically.

JMR-Ultra: New ultra-sized version for vertical lift aircraft with similar performance to fixed-wing tactical transport aircraft (the C-130J Super Hercules and the Airbus A400M Atlas). Introduction planned for 2025.

The initial foci are first on a medium-transport platform to succeed the Army UH-60 Black Hawk and Marine H-1 “Huey” utility helicopters—the Future Long-Range Assault Aircraft (FLRAA). Then a scout platform approximating the current Apache, now called the Future Attack and Reconnaissance Aircraft (FARA) with heavy-lift variants possibly following.

In March, the U.S. Army awarded Competitive Demonstration and Risk Reduction (CDRR) agreements to Bell and Sikorsky-Boeing for its FLRAA programme. On 25th March, the Army selected Bell and Sikorsky to continue phase two of the FARA Competitive Prototype (CP) programme.

Two Teams on FLRAA

Taking separate technological approaches, Bell and the joint Sikorsky-Boeing team have produced demonstrators for FLRAA, where the Bell V-280 is a tiltrotor aircraft resembling the V-22 Osprey, with engines and rotors at the end of its swivelling wings. The Sikorsky/Boeing SB>1 DEFIANT is a compound helicopter, with twin coaxial rotors providing lift and a pusher propeller to enhance speed.

Bell V-280 ‘Valor’

Bell’s V-280 is a combat force multiplier with superior performance, payload, survivability agility and reliability. Its design supports ground manoeuvres and is purpose-built for squad-plus enablers.

The helicopter has a V-tail configuration with a triple-redundant fly-by-wire control system for safe, precision aircraft handling. The system will reduce pilot workload and aircraft weight, minimising traditional flight control maintenance costs.

Safety and survivability are further enhanced through integrated cabin armour and state-of-the-art countermeasures. Bell’s design-to-build technology has significantly enhanced manufacturing, assembly and sustainability costs, with advanced tiltrotor speed providing commanders with more than twice the range of current helicopter platforms.

Valor’s mission equipment package enables en route situational understanding through digitally-fused reconnaissance, surveillance, intelligence and friendly-force information. The flexible design provides matching multi-mission versatility with exceptional 6000/95 hover performance.

The tiltrotor can rapidly self-deploy to any theatre, covering more than five times the area of current MEDEVAC platforms. The V-280 also provides a helicopter’s low-speed hover agility with fixed wing range and efficiencies.

While the V-280 Valor has a cruising speed of 280 KTAS (knots true airspeed)and combat range of 500-800nm, Bell has simplified the V-280 to swing the propellers but keep the engines stationary, which eliminates many moving parts and prevents the vehicle from scorching the ground during take-off and landing. The frame allows for a side-loading door, according to the Army’s preference, with a driveshaft running through the straight wing to enable both prop rotors to be driven by a single engine in the event of engine loss.

The V-280 has two spacious 1.83m side doors for convenient entry and exit of armed forces. Wings have a single section carbon-fibre-reinforced polymer composite, reducing weight and production costs, while it is designed to carry four crew members and 11 troops.

The helicopter is fitted with a conventional retractable landing gear for better control during take-off and landing. Dual cargo hooks give it a lift capacity to carry even a 10,000lb M777A2 Howitzer while flying at a speed of 150 knots.

Although the initial V-280 design is a utility configuration, this has not prevented the U.S. Marine Corps from reserving the aircraft to replace its utility and attack helicopters. Bell have ensured that the rotorcraft launches rockets, missiles and small unmanned aerial vehicles forward or aft with no rotor interference, even with the rotors forward for forward flight and cruise modes.

Overall, the V-280 is an exceptional ‘clean sheet’ next-generation tiltrotor thanks to Bell Helicopters’ six decades of expertise. The simplicity of this ground-breaking design can now deliver affordable, transformational technology to alter the course of vertical flight.

Sikorsky/Boeing SB>1 DEFIANT

Boeing and Sikorsky’s joint development of the SB>1 DEFIANT for the U.S. DoD reflects their status as lead providers of Attack, Assault and Heavy Lift Helicopters. Designed for the Army’s attack and assault missions as well as the Marine Corps’ long-range transportation, infiltration and resupply missions, the SB>1 DEFIANT is a fully integrated aircraft providing unmatched capabilities for the U.S. military’s various missions.

The Sikorsky and Boeing design achieves the right combination of speed, lift and range paramount to both assault and attack missions. Developed with 85 per cent commonality between attack and assault aircraft, the agile SB>1 DEFIANT reduces development and life-cycle costs while increasing overall manoeuvrability and ensuring minimal disruption or loss of existing rotorcraft expertise.

The X2 rigid co-axial rotor system is the base of the aircraft’s capabilities providing the U.S. military with evolutionary sustainability, affordability and readiness, proven airworthy through flights of the X2 and S-97 Raider. The two coaxial rotors on top rotate in opposite directions, with the extra lift from each rotor’s advancing blade balancing out the diminished lift from the opposite side’s retreating blade to eliminate retreating blade stall.

The back of the SB>1 DEFIANT mounts a pusher propulsor to provide the raw forward thrust for fast flight, allowing the aircraft to fly twice as fast and far as today’s conventional helicopters. This additional flight component also provides unique and unmatched manoeuvrability in all flight regimes including hover, low- and high-speed flight.

Improved agility and flight control augmentation allow tight assault formations with close proximity landings to deliver embarked troops as a cohesive unit, minimising exposure to hostile threats. Therefore, when folded for shipboard stowage, the SB>1 DEFIANT fits the footprint of a folded AH-1.

Competitive FLRAA Funding

On 18th March, the Army granted Bell and Sikorsky CD&RR project agreements for a two-year production effort. Through the Defense Appropriation Act, Congress has added US$75.6 million for competitive demonstration and risk reduction (CD&RR) in FVL.

FARA “Knife Fighter”

The Army calls the Future Attack Reconnaissance Aircraft (FARA) a “knife fighter” for the future battlefield. This out-front platform will fly into the most demanding and contested environments requiring maximum performance in a small package.

Five competitors originally developed technologies for FARA. Those awards went to AVX/L-3, Bell, Boeing, Karem Aircraft/Raytheon/Northrop Grumman and Sikorsky.

On 25th March, the Army narrowed the competition to Sikorsky and Bell for the final design, build and test phase, which is expected to provide the required data for a FARA contract award in FY2024. Sikorsky is already flying a prototype FARA, the S-97 Raider, while Bell has revealed its FARA concept, the 360 Invictus.

Sikorsky Raider X

Serving to redefine helicopter flight during the 21st century, Raider is a next-generation light tactical prototype helicopter capable of carrying six troops and external weapons.

Based on Sikorsky’s Collier Award-winning X2 Technology, Raider incorporates the latest advances in fly-by-wire, flight controls, vehicle management systems and systems integration. These technologies enable the aircraft to operate at high speeds while maintaining the low-speed handling qualities and manoeuvrability of conventional single main rotor helicopters.

Raider can reach speeds of more than 220 knots, nearly double the speed of a conventional helicopter. Designed for ‘high and hot’ operations, the helicopter is capable of flying at 10,000 feet in 95° heat.

In addition to serving the U.S. Army and Special Operations, the Raider X helicopter could potentially be applied to U.S. Air Force, U.S. Navy and U.S. Marine Corps missions. Moreover, the X2 Technology at the heart of the Raider helicopter is scalable to a variety of military missions, including light assault, light attack, armed reconnaissance, close-air support, combat search-and-rescue and unmanned applications.

Raider X is specifically designed for vertical lift dominance against evolving peer and near-peer threats in a joint all-domain environment. Leading up to a flight test programme, Sikorsky will further evolve and improve the design, development and build of the Raider X prototype. Raider X offers:• Reach in the form of speed, combat radius, endurance and payload

• Survivability through a revolutionary, game-changing leap in holistic protection, manoeuvrability and agility including a Modular Open Systems Approach (MOSA) that quickly adapts to new technology and threat capabilities.

• Lethality through a combination of speed, payload and manoeuvrability when deploying an array of sensor and weapon systems coupled with MOSA to field and employ new capabilities rapidly.

• Sustainment designed into the aircraft using a digital thread to decrease aircraft operating costs as new technologies shift from routine maintenance and inspections to self-monitoring and condition-based maintenance. These new capabilities will increase aircraft availability, reduce sustainment footprint going forward and enable a thread of flexible maintenance operating periods.

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

Speedy Bell 360 Invictus

Whether in the urban canyons of the megacity or rugged rural terrain, the design of the Bell 360 Invictus delivers advanced speed, range and agility. The robust, articulated rotor, lift-sharing wing and optimised tail rotor enables versatility in attack and reconnaissance operations across any environment.

A proven, articulated rotor head delivers greater speeds, while the high-speed rotor blade design mitigates retreating blade stall, providing agility in reconnaissance missions from hover to high speed. The lift-sharing wing reduces rotor lift demand in forward flight, enabling high-speed manoeuvrability without the need for a complex propulsor and drive system.

A digital thread allows real-time collaboration between production, supply chain and maintenance to facilitate smoother manufacturing, better sustainability, reduced downstream costs and mitigated schedule risks.

• A 3D digital twin provides a common data source throughout the life cycle of the aircraft, monitoring survivability and enabling test scenarios to be modelled while battlefield technology evolves.

• Design efficiency is achieved by reduced manufacturing, assembly, cost and rework time thanks to Bell’s programme approach and investment in technologies for high-rate manufacturing.

• A focus on modern manufacturing tools and processes increases affordability, while the mature design optimises reliability.

• The integrated supplemental power unit (SPU) serves dual purposes by providing auxiliary power for ground maintenance and systems checks. It also offers supplemental horsepower to boost cruise airspeed, dash speed, hover payload and autorotative performance.

Having been proven on the Bell V-280 Valor and Bell 525 Relentless, Bell’s advanced digital flight control system harmonises mature technologies for next-generation performance while offering an upgrade path to higher-level capabilities, such as optimally crewed flight operations. The system is triplex redundant and enables Level 1 handling qualities to ensure mission completion.

The Bell 360 Invictus also supports a 20mm cannon and internal payload featuring an integrated munitions launcher to accommodate current and future ordnance. The combination of advanced sensors and air-launched effects elevates situational awareness and increases lethality across the multidomain spectrum.

Army R&D Funding

FVL funding is carried in the Research and Development Army budget in PE 0603801A, Aviation Advanced Development. In FY2020, budget funding stands at US$107.6 million, while the FY2021 request is for US$134.4 million, going to US$653.7 million by FY2025. For FY2021, the FARA’s separate request is US$513.5 million under the same PE.

Since its inception, FVL has relied on industry-based investment to advance its technologies. Although the companies have not released exact figures, they have consistently pushed for the Army to increase its commitment to the R&D phase and define a deployment schedule and plan to inform corporate investment decisions.

Seeking Global Partnerships

The FVL programme is intended to benefit all U.S. military services, with the Army being the lead service providing the majority of funding from their budget. Still in an early stage, the FVL aircraft are not expected to be operational until the 2030s.

The U.S. Army is also working hard to find overseas partners who might be customers for the FVL’s future rotorcraft. The bigger the international footprint of Future Vertical Lift, the cheaper each aircraft will likely be for the Army and the more the American industry will benefit from this business.

Reference Text/images: www.vtol.org,

www.crsreports.congress.gov,
www.forbes.com,
www.nasa.gov