It is some 50 years since the UK aerospace industry produced a new training aircraft, the last being the Hawk TMk1 – although arguably the Hawk T2 was so different in many respects that it could, and perhaps should, have been called something else. All that may be about to change with the development of a new family of modular aircraft by a company called Aeralis. MS&T’s Dim Jones visited them in their new facility in Bristol. 

I first became aware of Aeralis some years ago through an ex-RAF colleague who was part of the original team. Their innovative plan was to produce a modular design in which a common forward fuselage and undercarriage section would be coupled with different wings and engine nacelles to produce a basic trainer, an advanced trainer and a display aircraft. I confess that my initial reaction, like, I suspect, many of my contemporaries was: ‘Nice idea, but it’ll never work – and even if it did, no one would be adventurous enough to buy it’. 

Well, the company has shown that the idea will work and, in the intervening years, enough large, influential and reputable organisations and aerospace companies have entered into collaborative arrangements with and provided financial backing to Aeralis to suggest that there is every chance that there will be a market for it.

Aeralis is the brainchild of its founder and now CEO, Tristan Crawford, who spent many years working in the aerospace industry, but principally in the civil sector. He recognised that many air forces were struggling with their flying training pipelines, and specifically with the number of platforms they were using and the associated lack of flexibility and cost of ownership. In his work with Airbus on variants of the A300 series, he considered that two characteristics of their operation could be transferred to the military environment. The first was interchangeability of components to suit customer requirements, in the case of airliners such items as wingtips and engines; and the second was the ownership model, in that 52% of today’s airliners are leased by their operators rather than owned. At this point, the UK was concentrating on component and supply-chain activity, and had ceded whole-aircraft authority to other nations. Tristan Crawford then moved to QinetiQ at Boscombe Down to gain whole-aircraft experience as a trials officer on the Harrier GR7, and was struck by the sight of a Tucano and Hawk T1 sitting next to each other on the ramp, essentially performing similar tasks, but with entirely different components and support equipment; there must be scope for rationalisation initiatives, such as a common core fuselage.

Finding Funding

First stop in the quest for funding was UK Defence & Security Exports (DSE), where the view was that the idea was feasible, and the timing was good – many training fleets around the world were showing their age, and there was nothing much new in the pipeline: it was not apparent, for instance, that BAE Systems were developing a new training aircraft beyond Hawk. Cost analysis and marketing studies suggested that a common basic and advanced trainer would generate a 35% saving in through-life costs, and further variants would increase this figure. Manufacturing feasibility was not an issue, since there would be no fundamentally new technology involved, and Tristan Crawford was never in any doubt that the concept was practical; to quote him: “Compared to operations in the civil sector, this should technically be a piece of cake”. The next step was more serious funding, and this was provided to a limited extent by the RAF’s Rapid Capability Office, which predicted correctly that it could be used to leverage additional support from organisations with which it worked, such as a Sovereign Wealth Fund in Qatar, now known to be Barzan Holdings.  

Subsequently, such illustrious companies as Thales, Siemens, Atkins and Rolls-Royce have entered into collaboration agreements with Aeralis, and there are currently 135 people from 16 companies engaged in preliminary design work; there is ample expertise within UK in all facets of design and production. Aeralis is in discussion with the UK MoD about its future requirements, and a Memorandum of Understanding was recently signed with Ascent Flight Training, the consortium which currently provides the UK’s Military Flight Training System (MFTS).

Variants of Variants

The aim is to produce a suite of aircraft which combines capability with affordability.  While being very aware of the performance parameters of the US T-X (T-38 replacement) programme, but also of the size and cost of the designs which were offered, Aeralis’s experience and research indicates that, above about 7 or 8t Maximum Take-Off Weight and 3 to 4t Empty Mass, costs tend to rise exponentially; these figures allow for about one tonne of fuel, one tonne of payload and a ferry range of about 1000 nm. In terms of performance, and using the Advanced Jet Trainer (AJT) variant as a benchmark, the Aeralis aircraft would provide the level of agile flight performance needed to allow a student to demonstrate skills such as airmanship, formation, navigation and G-awareness, while enabling the development of techniques, by incorporating advanced avionics to replicate the systems, data and sensor management of more expensive front-line aircraft; indeed, the cockpits would be reconfigurable to match a specific operational type. Live, Virtual and Constructive (LVC) technology would be incorporated from the outset, with a supporting suite of synthetic trainers, and Aeralis envisage a modular syllabus with performance-based progression.

Since its inception, the scope of the programme has expanded and, in addition to the basic, AJT and display variants, there is the potential for incremental development of: 

  • an aggressor aircraft, with sensors and emitters; 
  • a naval variant, incorporating fuselage modifications, arrestor hook and strengthened undercarriage for deck operations; 
  • uncrewed variants, carrying out roles such as ISTAR and air refuelling; and 
  • light combat variants, crewed or uncrewed (loyal wingman), carrying a variety of weapons. 

When used as part of a combined fleet, there will be 85% commonality of components and above 50% through-life cost reduction. The reconfigurable components comprise: wings and associated lift devices, including a high-aspect variant and optional Leading Edge Root Extension (LERX); cockpits, either dual, single or uncrewed (the additional space available in the latter options could be used for avionics or fuel), and with cockpit systems to match the intended role; tail unit, either conventional or reduced-observable V-tailplane; and engine(s), single or twin.  Engine options will satisfy the requirements of customers who are aligned with certain manufacturers, and those who – for reasons of desired performance or safety – prefer a twin-engine configuration. The concept of an engine nacelle mounted on the fuselage, but structurally separate from it, is unique and has been patented by Aeralis.


Exploded view of Aeralis modular design concept. Image credit: Aeralis.

Ownship Ownership

Another programme innovation concerns ownership. Over 50% of aircraft in the commercial aviation world are now owned by specialist leasing companies, rather than the airlines. This allows the airlines to have available the number of aircraft they need when they need them, and in the configurations they require. These are not big companies; there are only 12 of them yet; four of these own half the aircraft leased. In a slightly different environment, the same could apply to military flight training; the number of aircraft, and their configurations could be varied to suit the customer’s changing needs in the training pipeline, and the leasing company’s focus would be entirely on delivering airframe hours in the required configurations. It would also allow the leasing company, rather than the customer, to hold stocks of the various module options, thus conferring economies of scale.  

The whole design, manufacturing and support process is underpinned by a digital environment. Only two companies possess the toolsets to create this environment, and the means of allowing the various toolsets to talk to each other and – the ‘digital fabric’ – and Aeralis have teamed with Siemens to create Aerside, which enables a digital network of the entire programme: from requirements through systems modelling and software development to Test & Evaluation, but thence to production management, fleet management and supply-chain management. Indeed, such are the vagaries of the physical test environment that inherently controllable synthetic modelling can be more consistent than physical testing, and the data thus acquired, once tested for validity against physical test evidence, can be used later for certification purposes. This supports the aspirations of the Civil Aviation Authority (CAA) and the Military Aviation Authority (MAA) – both of whom are supportive of the programme – for a more streamlined certification process, and could lay the foundations for development of future air systems, the risks and costs of which would otherwise be unsustainable and unaffordable.

Demonstrator in 2025

The development of the aircraft and its variants is planned in a roadmap of low-risk ‘tech steps’, in which each step de-risks the next, and starts with the modular demonstrator in 2025. The baseline variant will be the AJT in 2028 and then the development really starts with later variants in around 2030. A single-seat configuration will allow extra fuel or avionics, and it will be a question of what the customer wants in terms of airframe and systems performance. Aeralis has worked with Rolls-Royce to produce additional electrical power generation capability such that advanced EW systems can be fielded, and the nose module can accommodate either radar or threat emulator. The aggressor design point could also cover a light attack capability, just as the AJT would be the basis for a display aircraft. The naval variant in 2031 would need modifications to the fuselage for deck landings, and an uncrewed version in 2032 with options for engine, hi-aspect wing and agnostic flight control system.  

At this point, there would be scope for some of the ‘net-zero’ propulsion systems – electric and hybrid – and finally the ‘loyal wingman’ combat variant in 2033 with a low-observable V-tail and the addition of weapons. Lastly, although not a specific design variant, there could be a market for a front-line companion aircraft. As the constraints on live flying, particularly of Gen 5 aircraft, become greater, and the Live-Synthetic Balance becomes more weighted towards synthetic, there will be a need for pilots to gain live-flying experience on less expensive aircraft but, crucially, with comparable performance and representative systems. Using the uncrewed version, there would also be scope for a tactical tanker, along the lines of the MQ-25 being developed by Boeing, and of the same order of size and offload as MQ-25 and the previously successful Douglas A-4 Skyhawk ‘Buddy’ air refueller.

Key to the Aeralis operating concept is availability, with the user concentrating on getting the aircraft in the air doing their jobs, and the supporting companies focusing on providing the required airframes in the specified configurations. The aircraft service concept is being developed through such organisations as Affinity, providing a range of aircraft as a service to the UK Military Flight Training System, and AirTanker – a leasing company consortium of Airbus, Rolls-Royce, Babcock and Thales, which operates the Airbus A-330 MRTT Voyager, and achieves availability of over 85% – in the provision of air refuelling assets to the RAF and RN. 

Support Shift

The past 25 years have also seen a major shift in the way UK air forces have been supported: from the organic support model of the Cold War and 1990s; through Integrated Logistic Support to the focus on platform availability enshrined in the Strategic Defence and Security Review (SDSR) 2005; to the current ‘partnered enterprise model’, which aligns KPIs and promotes joint problem solving. The trajectory throughout has been a progressive transfer of risk from government to industry, and the next milestone – SDSR 2025 – could see the trend continue towards the agile acquisition and delivery model on which the Aeralis strategy is based.            

Stages 1 (Feasibility) and 2 (Concept Design) of the Aeralis plan are complete.  Stage 3 (Pre-Production) is ongoing, and will include a first flight in 2025. This will be followed by Certification from 2025 to 2027, and finally full Production after 2028.  This coincides with a period in which many air forces’ training fleets will be approaching the end of their service lives and will require replacement. The Boeing T-7A Red Hawk is an obvious contender but has a backlog of production to work through for the US market, and a level of performance – and commensurate cost – arguably beyond the requirements of some customers. Joint training ventures, such as the Euro-NATO Joint Jet Pilot Training programme (ENJJPT) at Sheppard AFB in the US, NATO Flying Training Canada (NFTC) and, more recently, the International Flight Training School (IFTS) in Italy have shown that there is an appetite for collaborative flying training, into which the Aeralis concept could fit very neatly.

There are currently 135 people across 16 organisations working on Aeralis development. The company calculates that, within the next decade, 600+ aircraft in trainer and aggressor roles alone will require replacement by nations as diverse as Australia, Japan, Sweden and Canada – not to mention the US Navy’s requirement for a T-45 replacement – and, of course, the UK which Aeralis regards as a key potential launch customer. The market is there, the trend in support is increasingly towards availability contracting, leasing is an attractive alternative to ownership, and the modular concept has been shown to be feasible. From a ‘nice idea’ to an emerging reality, the Aeralis model has come a long way in a short time, and we will observe the upcoming developments with keen anticipation.