Military Rotorcraft Development

Defiant X and Raider X Future Vertical Lift rotorcraft.
Sikorsky/Lockheed Martin states that its digital backbone will reduce risk, cost, and increase efficiency for its Defiant X and Raider X Future Vertical Lift rotorcraft.

New rotorcraft are going to come with new abilities founded on open systems that provide easier upgrade paths and cheaper through life costs.

The main manufacturers of military rotorcraft in the United States and Europe are at various stages of substantially transforming the performance of their designs for what will be their future platforms. The driving force behind this is the adoption of digital technology and improved manufacturing techniques and materials.

But it is also the product of the last 20 years of counter-insurgency campaigns, where many helicopters were proven to be unsuitable for operations in ‘hot and high’ conditions, particularly those experienced in Afghanistan.

However, the rule is never prepare for the conflict that has just gone. With the chance of peer-to-peer or near-peer conflict now resurfacing, there are more elements to consider above range, speed, endurance and improved maintenance, although these remain key attributes that virtually all military rotorcraft need to have.

More than ever the rotorcraft must be part of the military network, whether gathering intelligence, surveillance and reconnaissance (ISR), acting as a communications node or delivering kinetic effects to the standard airborne logistical transport asset.

To do this, they must be able to share voice and data in real time. They must also be able to operate close to, or in, the opponent’s anti-access aerial denial (A2AD) zone – particularly those with a kinetic role.


US Army Aviation Future Long Range Assault Aircraft (FLRAA) and Future Attack Reconnaissance Aircraft (FARA) are due to be fielded around 2030. The main US rotorcraft manufacturers of Bell, Boeing and Sikorsky/Lockheed Martin are the primes with a variety of compound and tiltrotor designs.

The two contenders for FLRAA are Bell’s V-280 Valor tiltrotor and Sikorsky/Boeing’s Defiant X coaxial, both of which emerged out of the US Army’s Joint Multirole Technology Demonstrator (JMR-TD) project. Both Bell and Sikorsky are again in competition over FARA. Bell is offering its 360 Invictus while Sikorsky its Raider X.

Teaming with industry is one of the crucial aspects of any development programme, with recognised organisations bring their particular technology experience. Bell’s team Invictus include Astronics, Collins Aerospace (part of Raytheon), GE Aviation, ITT-Enidine, L3Harris, Parker Lord, Mecaer Aviation, MOOG, and TRU Simulation + Training. While some of the same companies are also part of Team Valor, others companies include Eaton, GKN Aerospace, IAI, Lockheed Martin (also of course a key player in  Sikorsky’s competitive platforms), Rolls Royce and Spirit Aerosystems.

Sikorsky/LM’s digital design and manufacturing is aimed at lowering acquisition costs while allowing rapid and affordable upgrades over time.

In August 2020, Bell opened a new Manufacturing Technology Center (MTC) at its Fort Worth headquarters. The drive to find solutions and to develop technologies and processes in line with the DoD’s ongoing upgrade requirements for its FVL aircraft is the reason for this development. Although the down select of both the FLRAA and FARA is over a year away, the MTC will focus on the refinement of core technologies including rotor and drive systems, critical infrastructure and final assembly. Incidentally, this will almost certainly also be extremely useful to the company in its development of of its civilian rotorcraft range.

Glenn Isbell, vice president, Rapid Prototyping & Manufacturing Innovation said that ‘future factories’ such as the MTC would allow industry partners and teams to work more in harmony with each other throughout the development and sustainment of any platform. With the backbone of future platforms centred around digital connectivity and integration, system architecture can be built and tested by industry before ever getting close to the aircraft for which they are intended.

“These future factories working together with our teammates and suppliers, will be designed to enable high-quality, high-rate production of the Bell V-280 Valor, Bell 360 Invictus and other future aircraft.”

The MOSA challenge

Modular Open Systems Approach (MOSA), formerly known as modular systems architecture, has been adopted by the US Army to allow the flexible integration of major systems and their component parts, and between systems and their host platforms.

MOSA will be central to all of the new US Army Future Vertical Lift contenders, so that army aviation can benefit from accelerated integration of capabilities, significantly reducing non compatible architectures.

An enduring block to rapid platform development and systems upgrade on military rotorcraft was due to the fact that rotorcraft operators have been tied into proprietary technology which traditionally has meant waiting for the development of expensive upgrades over which the operator had little or no control. This meant that there was very little flexibility to control cost or through life upgrades to the platform.

FLRAA Bell V-280 Valor
Bell is integrating the Modular Open System Approach (MOSA) with both its FLRAA Bell V-280 Valor and FARA Bell 360 Invictus developments. The Open Architecture Digital Backbone allows both the integration of currently fielded mission system equipment as well as new technology.

“MOSA will let us align the strategies for standards and interfaces said Colonel David Phillips, project manager, FLARA US Army. During the same conference, Matt Sipe with the MOSA Transformation Office at PEO Aviation said MOSA represented “a tailored approach for addressing and resolving challenges”, adding that they didn’t want to be reliant on “any particular vendor’s box.”

Sipe said that one of the key advantages of MOSA  was that with rapidly developing technology it allowed the US Army’s rotorcraft “to stay modern and stay relative.” Meeting the threat offered by technologically advanced peers meant continually adapting to the battlefield: “we need to maintain the high ground.”

In order to achieve this standardisation and drive to eliminate proprietary ‘stovepipe’ development, MOSA will focus on nine Lines of Effort (LoEs): governance and policy; architecture and standards; software development; collaborative digital environment; MOSA conformance centre; qualification and material release; affordability and savings; contracting efficiencies; and strategic communications. The end result should be to ensure that future fleets are affordable, sustainable, and upgradeable as the Army encounters threats that change and evolve.

Nato Medium Rotorcraft Expected Out of Service Dates

  • 100 Mil Mi-8/17 in 2030–35
  • 191 Aérospatiale SA 330 Puma in 2030–40
  • 167 Sikorsky S-70/UH-60 in 2030–40
  • 143 Leonardo AW101 in 2035–40
  • 331 NHIndustries NH90 in 2040–45

Europes NGR

NATO’S Next Generation Rotorcraft Capabilities (NGRC) Team of Experts (TOE), after years of building analysis and deliberations are backing a proposal for a new medium multi-role helicopter that will be developed by industry with a proposed delivery date of around 2035.

The conclusion was reached when analysis of rotorcraft currently in service revealed that close to 1,000 medium helicopters across NATO forces would reach their out of service date date between 2030 and 2050.

To date, the NGRC TOE has deliberately not focused on a type of platform that might be suitable, such as rotor configuration, number of engines and internal size, although an airframe weight of between 17,600lb and 33,100lb (8,000kg – 15,000kg) has been loosely suggested.

The NGRC is one of NATO’s high visibility projects, listed as a high end acquisition requirement alongside the Multi Role Tanker Transport Capability (MRTT-C), Maritime Multi Mission Aircraft (M3A), Maritime Unmanned Systems (MUS), Modular Solution for Ground Based Air Defence Capabilities (Modular GBAD) and Rapidly Deployable Mobile Counter Rockets, Artillery and Mortar (C-RAM).

Lieutenant Commander, Andrew White, Royal Navy, Capability Air Manoeuvre with UK armed forces and also Secretary for the TOE during a discussion on the subject hosted by the Royal Aeronautical Society’s Rotorcraft Group in January that studies have shown that a medium helicopter is usually the most cost efficient platform across the majority of missions. In terms of practicality it is also very transportable either as a tactical or strategic asset.

But why now? Lt Cdr White pointed out that it has traditionally taken around 20 years to develop a new rotorcraft. The first NATO advisory group meetings on NH-90s occurred in 1981 but first aircraft deliveries did not take place until 25 years later. He said that multinational projects could be particularly difficult, but with NGRC and its focus on developing the concept first, difficulties could be avoided in the long term.

“The fundamentals of how to control a rotorcraft haven’t really changed, however advanced inceptors, fly-by-wire technology, and active control allow decrease in weight, increase in responsiveness and agility,” said White. “Also the modular open systems approach is absolutely fundamental to the future and is the driving force behind many programmes and products and is absolutely key.”

Artificial intelligence and machine learning into an onboard or remote crew is also getting to be a fundamental requirement for a new generation of rotorcraft. There is also potential to consider self-protection and kinetic firepower. “One point we have briefly looked at is directed energy weapons however it is an open area that we are keen to export,” said White.

New materials and manufacturing mean, stronger, lighter and more robust aircraft in the future. Greater situational awareness will also increase aircraft survivability added White.

In October 2020, a Letter of Intent (LoI) was signed by the Defence Ministers from France, Germany, Greece, Italy & UK which meant that work could begin on defining a Statement of Requirements which would lead to the more precise defining of what the NGRC would be and what it could deliver. As various national requirements will undoubtedly emerge, it is believed that this early identification of the concept of the NGRC, combined with a MOSA like framework to build upon will avoid the difficulties and delays that were inherent in the NHI NH-90 programme. The Defence Ministers are scheduled to return in 2022 to sign a Memorandum of Understanding which would initiate the concept phase.

The Defence Ministers of France, Germany, Greece, Italy and the United Kingdom have signed a Letter of Intent (LOI) binding them to a national commitment to develop a new medium multirole helicopter through NATO’s NGRC Project.

The NATO Industry Advisory Group (NIAG) has also been examining the capabilities, sustainability and acquisition processes behind the NGR. This takes in through life costs, modularity and conditions based maintenance so that the aircraft are interoperable, sustainable perhaps most importantly affordable not only at their acquisition, but through their operational lifetime (supporting changing mission requirement) through to their out of service data.

Paul Kennard, director at Ascalon Defence Consultancy with experience founded in the Royal Air Force (RAF) as an air domain future technology requirements manager, observes that the fundamental requirement for an NGR will be significant increases in speed, altitude and radius of action – in fact similar to the attributes desired by US Army aviation.

However, he points out that there are many different aspects to the requirements future rotorcraft will have, particularly in the heightened threat environment of near peer conflict. And this is where the modularity (backed by a MOSA type structure) will be important.

Kennard underscores the need several vital mission systems: certified Degraded Visual Environment (DVE) systems (for white/brown out conditions and low light), cyber harding and electronic warfare survivability (particularly when operating near or in an Anti Access/Area Denial (A2/AD) environment), and the ability to conduct manned and unmanned teaming (MUM-T).

Optionally piloted rotorcraft have been tested for some years, and could be used for very dangerous insertions or simply ‘ash and trash’ missions along benign flight paths where crews could be rested for more important tasks. This would increase the number of task missions that could be flown in a 24 hour period, perhaps reducing the actual number of aircraft needed in theatre, as long as health and usage monitoring could allow the maintenance crews to keep the aircraft compatible with the number of flight hours.

Lars Ericsson of the NATO Joint Capability Group Vertical Lift and Army APEO Aviation for Engineering and Technology concludes by underlining the unqualified benefits MOSA will bring: “it gives us rapid upgradability with dramatic reduction in cost and fielding. We need to keep pace with [technological] improvements and buy into capabilities that fit the MOSA framework.”

International militaries will not be able to avoid the success of programmes such as FLRAA, FARA and NGR. Joint and combined international operations will rely on partner countries being able to operate in coordination with highly capable next generation rotorcraft, and need to start planning now for their own transformation to the next level of capability.

by Andrew Drwiega