Can the UK’s light modular aircraft developer, Aeralis now make the jump to production and sales success? TIM ROBINSON FRAeS reports from an industry day, held in April.
First revealed in the pages of AEROSPACE in August 2015 as the then named DART Jet, the UK’s Aeralis has spent the last decade quietly working in the background, designing and refining its innovative idea for a light jet trainer and multi-mission aircraft. Through a ‘digital first’ design approach and a modular concept, its aircraft offers a staggering 50% reduction in through life costs.
Mix-and-match modular jet
The modular design of the aircraft means it can be adapted for various uses. (All images from Aeralis unless stated)
Key to the vision of Aeralis’ founder and CEO, Tristan Crawford is taking lessons from the civil aviation industry, particularly Airbus where part commonality between its single-aisle family (from the baby A318 to globe-spanning A321) allows for production efficiencies and economies of scale, and for customers to ‘right-size’ their fleets to match demand. With military pilot training systems seemingly swinging between ‘feast or famine’ with either too many aircraft of one type or not enough, Crawford’s disruptive question was to ask: ‘why can’t this be done for a military aircraft?’ Aeralis’ concept is, therefore, a very simple, lightweight jet aircraft with an aluminium structure, using as many existing parts and components as possible. For example, the landing gear is derived from the BAE Hawk. However, the aircraft is built in a modular way where only the Common Core Fuselage (CCF) remains the same and the wings, tail and engine(s) can be swapped to configure different variants of the same design.
While not an overnight task, this flexibility (combined with a common pool of spares) would allow customers to flex their training fleets and mix and match to meet training or even operational demands, achieving significantly higher levels of availability. Allied to this is the option that, while some customers may want to own the assets, Aeralis is proposing a UK AirTanker-like business model used by service providers, where the customer pays for only the flying hours – with no capital expenditure and upfront costs – and training commoditised. Since it was first unveiled in 2015 as a basic/advanced trainer with options for straight/swept wings, the company has got a new name, Aeralis, and the concept has expanded to include high-performance display and aggressor variants, as well as uncrewed ISR and tactical tanker versions.
The modular design, much like Airbus’ international production and FALs around the globe also lends itself to ‘national variants’ of the aircraft which could be designed, produced and assembled locally. The aircraft itself has also evolved from the original configuration of a high-wing design with sponsons for the landing gear. Tweaks to this design saw Aeralis reveal a new low-wing configuration in 2023 which has improved the top speed and simplified the landing gear integration. With a new top speed of Mach .92, 20°+ AoA and 8G limits, the redesign also gives better transonic performance, according to Chief Engineer, Tim Williams. This performance now means the jet is able to meet almost all but the most demanding of roles, yet still remain affordable and simple.
The objective, says Aeralis, is to get the despatch reliability of a civil airliner to generate the training capacity air forces need and reduce the expense of combat exercises where no ‘aggressor’ aircraft show up due to poor serviceability. Engine-wise, while the company has selected the Honeywell F124 for its Advanced Jet Trainer variant, it is also looking at Japan’s IHI F3 which would suit a twin-engine configuration, along with the Ukrainian Ivchenko-Progress AI-322. Furthermore and should demand encourage it, a Rolls-Royce and Safran Anglo-French future engine option – leveraging the digital design approach trialled on the Orpheus small engine technology demonstrator – could provide for a future sovereign powerplant.
Industry partners
A mock-up of the Common Core Fuselage (CCF) on display at Aeralis’ industry day in Gosport, UK in April.
The industry day saw Aeralis showcase its supplier team – called Aerteam – and assemble at the StandardAero facility in Gosport, UK to give VIP guests from investors, air forces, industry, regulators and the media a vision of how this highly experienced enterprise will come together to develop, build and deliver a clean sheet modular light jet trainer.
MRO specialists, StandardAero, for example would equip the CCF, while Hamble Aerostructures (with a lineage to Folland and the Gnat) would design and build the CCF airframe, including the canopy, which it already provides for the Hawk. Meanwhile, Honeywell/ITEC is the primary engine supplier with the F124 and can also provide the OBOGS (on-board oxygen generating system) and ECS (environmental control system). The F124 is particularly robust, having never had a controlled surge nor a shutdown due to bird ingestion. Landing gear specialists, Héroux-Devtek will provide the undercarriage and Martin Baker the ejection seats. Meanwhile, Leonardo will provide the large area display (as used in the M346 Block 20) and the fly-by-wire system, with the company also supplying the FBW for the TAI Hurjet.
For the cockpit, the large area display (and back-ups) will allow a representation of primary displays for basic training, as well as an emulation of Eurofighter, F-35 or even GCAP-style displays via open system software. The company also revealed that it is considering using active stick technology for the sidesticks and throttles – which provide tactile cues of stalls and soft limits for advanced manoeuvres. Aeralis is also using the UK MoD’s new Pyramid open system architecture standard for avionics and mission systems – which decouples the flight control software from mission systems – allowing for faster, cheaper and smoother upgrades. Siemens, meanwhile, is providing the NX digital design software (also used for Tempest) that capitalises on parametric data for digital twins and rapid iteration, as well as the live digital mockup of the aircraft. By using this system, changes can be rapidly incorporated, ergonomics tested and maintenance factors addressed, for example putting the most reliable Line Replacement Units (LRUs) furthest from the access hatches. The digital design also includes the latest Model-Based Systems Engineering (MBSE) where, for example, the fuel system can be tested in simulated inverted flight using advanced fluids modelling. The live digital mock-up also allows real-time collaboration on a single virtual twin of the aircraft – with any changes rippling through the design and updating automatically. This also extends to an ‘industrial metaverse’ in designing a clean sheet factory, production line and support, as well as the airframe itself – allowing for production efficiencies to be optimised and factors, like shift patterns and the shop floor layout, to be taken into account with a ‘digital twin’ of the factory itself. A whole production cycle can, therefore, be simulated in minutes, allowing bottlenecks to be identified. Interestingly, another partner is AR training start-up, Red 6, which would have the opportunity to integrate its cutting-edge AR headset into a clean sheet jet trainer to provide seamless BVR to visual training with virtual ‘bandits’ and ‘wingmen.’
No location has yet been confirmed for final assembly, but Prestwick has been mentioned, as well as a sister FAL in France. Like Airbus’ global network of FALs, the aircraft modular construction lends itself to a ‘light’ local assembly – which could even be very close to or co-located with air force customers themselves. Should production go ahead, this could support 6,300 jobs across the UK and France.
Digital certification
Much of the design has already been done using cutting-edge digital engineering tools.
As well as the modular concept, another innovation that Aeralis brings is its AERSIDE digital certification pathway, which is understood to be a first in military aviation. It allows the regulator to log in and check progress at every stage, approving/commenting as the project develops, with any requested changes passing through the system to update it and the evidence delivered in a format that the regulator understands and accepts. This next-generation digital certification model is already attracting interest from other companies who are keen on applying it to their own programmes.
Notably, Aelaris is targeting EASA civil certification, whilst also achieving full clarity to deliver UK CAA and MAA approvals. The company is now working to a critical design review (CDR), followed by a digital, then a real, first flight 42 months following customer commitment. This will be followed by a two-year flight test campaign with four test aircraft, culminating in type certification and first delivery in 2030 if a go-ahead is given this year – just when the Hawk is expected to go out of RAF service. Five years for development and delivery of clean sheet military aircraft seems an ambitious goal, yet it is important to remember that this design work has stretched back a decade. Furthermore, the rapid advance of digital design tools, MBSE, simulation and AI have helped to accelerate development and virtually mature the aircraft to the point where cutting metal should theoretically be the simplest part of the process. As Crawford wryly notes, when asked about this timescale: “We’ve been doing this for five years already and, given we have this safely digitised, if we don’t fly in three and a half years, we will have done something badly wrong.”
French connection
Like the Red Arrows, the Patrouille de France is in need of a replacement aircraft.
However, Aeralis enters an increasingly crowded and competitive global military trainer market against the Boeing/Saab T-7A, Lockheed Martin/ KAI T-50, Leonardo M-346 and TAI Hürjet, as well as the Yak-130 and Chengdu L-15. To that end, the company has widened its horizons by establishing Aeralis France and targeting the wider European trainer market – with EASA certification opening further opportunities.
Like the RAF, the French Armée de l’air et de l’espace is also staring at obsolescence issues with the Patrouille de France’s ageing Dassault Alpha Jets and, while it has decided on a direct Pilatus PC-21 to Dassault Rafale syllabus, there are similar requirements to the UK. Says Crawford: “It gives us a way to actually certify the aircraft in Europe, so we’re then able to operate the aircraft freely across all EU member states, which we couldn’t do under a purely British type certificate after Brexit.” Says Crawford of Aeralis’ vision for an entente cordiale: “There should be a UK and French bilateral programme under the Lancaster House Treaty, to co-develop this relatively simple jet-like aircraft system to solve the problem of display, trainer jets because both nations have very, very similar gaps. Its non-contentious and off-the-shelf and a purely collaborative programme.”
Qatar too, with its major investment through the Bazan sovereign investment fund, is likely be an early customer. Japan is also in the frame and looking for a replacement for its ageing Kawasaki T-4 fleet. Here too, Aeralis may be able to leverage deep Anglo-Japanese defence ties through the GCAP programme and local Japanese industry using Aeralis’ CCF to rapidly develop a Japanese designed and built aircraft. As well as the UK, France, Qatar and Japan as possible launch customers, the firm says there is a viable and very conservative global sales forecast of around 500 aircraft. For the UK, it predicts a requirement for 20 advanced jet trainers (AJTs) to replace the Hawk T.2, 15 aggressors and 15 aircraft for the Red Arrows. France, meanwhile, is reportedly looking at 20 companion trainers, 15 aggressors and 15 for the Patrouille de France, while Qatar is estimated to need 20 aircraft, split between AJTs and its display team. All told, these add up to 120 aircraft as an initial batch to launch the programme.
Crawford is also confident that Aeralis will grow from a British trainer to a European one, especially with the F-35 force growing to 500 aircraft in Europe by 2030. This number of fighters will need additional trained aircrew and, on top of expanding Eurofighter and Rafale fleets, this means that even with other trainers in contention, there is a growing need for new training aircraft. The need to prepare pilots for 4.5./5 and 6th generation aircraft, as well as provide supporting functions, such as aggressors, uncrewed platforms and companion trainers, means there is significant demand across Europe and beyond. Notes Crawford: “The way this product is going to scale up is through the European market, because of the massive gap in training capacity and the lack of a budget to spend a lot of money. I’m confident that ultimately Aeralis will become a European programme certified under EASA civil rules that can be supplied through a service provider that anybody in Europe can buy hours from.”
A British aircraft for the Reds?
The Red Arrows are in need of a new display aircraft.
The selection of a new RAF trainer also comes with the additional political baggage in that any new AJT might also replace the ageing Hawk T.1 As operated by the Red Arrows. Though the future of the team is not set in stone, it would be a brave politician who would announce that the ‘Reds’ were being axed. Furthermore, as well as the recruitment role, the Red Arrows play a part in showcasing UK aerospace and defence industry across the globe – by flying a British-built aircraft. With the Hawk now out of production, the only UK-designed and developed trainer aircraft will be from Aeralis – but is this aerial ambassador role still important these days?
This issue has become a regular topic for questions in the UK’s Parliament – with Defence Secretary, John Healey MP telling the House of Commons in May: “This is a government that will first of all look to direct British taxpayers’ defence investment to British-based firms, British-based jobs, British-based technology and British-based innovation,” when considering the options. Beyond UK politics, since 20 January there is also now a wider geopolitical aspect to purchasing US equipment – especially in Europe where there is growing movement to develop and purchase homegrown aircraft and weapons. In terms of Western-built fifth-generation stealth fighters, there are few choices beyond the ubiquitous F-35 – but in trainers there are now two and potentially three European products from Aeralis, Leonardo and now Türkiye’s Hürjet (the latter recently selected by the Spanish Air Force as its next trainer).
Summary
Could Aeralis’ product fulfil the requirements of the RAF and international customers going forward?
With Aeralis having completed an unprecedented amount of design work already and having assembled credible and highly experienced industry suppliers, all that awaits is a firm commitment from a customer to unlock the next stage of private funding and kick off the next stage of development and a countdown to first flight. Says Crawford: “We’re now reaching the end game for our company that is now pulling together the industrial consortium.” He adds: “we’re now in that timing window for the UK, France and Europe to start to commit to a future advanced jet trainer.” In some eyes, this disruptive concept from a small start-up still remains an unknown bet. However, if taking a chance on a small start-up remains a risk then so do the potential gains – a potential UK export success, revitalising Anglo-French relations and slashing through-life costs by half, with private investors funding development and customers just paying for training hours. However, the clock, at least if the UK wants a Red Arrows replacement with no large gap after the Hawk leaves service, is now ticking. As Crawford says: “From our perspective the UK needs to get going – we’ve got the right product at the right time in the right place.”
