Tempest: the stealthy and stress-free future fighter plane

Fighter pilots of the future will operate in a different world. They’ll have more facts at their fingertips, more help from advanced processing, artificial intelligence, augmented reality and laser precision weaponry and drones – aided by algorithms that haven’t even been created yet. This is the UK’s Tempest combat air system, announced in 2018 and under development around the country.

As one programme partner puts it, a Tempest pilot will have the situational awareness of Iron Man on a mission – or Luke Skywalker’s faith in The Force as he flies into the Death Star.

Tempest is one of several sixth-generation fighter jets being developed around the world. In a multi-billion-pound project, a stealth airframe will incorporate a host of intertwined open-architecture technology, built to adapt to changing threats. Due to enter service around the mid 2030s, it could eventually fly uncrewed, but for now, there will be a human being on board – though the co-pilot may be virtual.

Tempest is a project of firsts for the UK. With a record fast turnaround – twice as fast as predecessor Eurofighter Typhoon back in the 1980s – and involving five core partners, its design is taking place digitally and in parallel. And partners must keep the costs down. “Every aspect of our lives has changed since the last aircraft was designed in the UK,” says Andrew Howard, director of major air programmes UK at Tempest partner Leonardo. “The quantum change is extraordinary.”

Unanswered questions remain, though, concerning costs, levels of automation around use of weapons, and whether further international partners will come on board. Those in charge say they are still open to collaboration with interested nations.

Team Tempest is currently working with some 200 smaller businesses around the country and a scattering of universities from Strathclyde to Cranfield, and is in discussion with 600 suppliers, small businesses, and universities in total. The Ministry of Defence and industry partners are embedded in each other’s teams for swifter decisions and better understanding. And for the first time, the staid defence sector is borrowing human-machine interfaces and simulation technology from the gaming and automotive worlds.

Tomorrow’s skies will be rife with new and evolving threats – from hypersonic weapons to hostile drones and electronic warfare. But pilots will be aided by some hefty computing muscle capable of processing a city’s-worth of data in a second, by fleets of uncrewed smaller fighters (drones) to fly alongside, and by adaptable technology.

Later this year, Tempest will move to a concept and assessment phase, and partners say it’s on track for a prototype in the mid-2020s. The programme is led by BAE Systems, the UK’s largest defence firm, which is collaborating with Sweden’s Saab and Italy’s Leonardo to spread the financial load, with Rolls-Royce and missile manufacturer MBDA making up the lead partners overseeing a 2,000-strong team.

“It will still have wings, wheels and a cockpit,” says Howard. “But whereas Typhoon was developed with primitive computing power, this is a digitally enabled design exploring the art of the possible.” Tempest is often described as a ‘system of systems’ – which doesn’t do justice to the scale of collaboration required. A future system will connect across air, but also land, sea, cyber and increasingly space, says a BAE Systems spokesperson. This will give a more complete picture, fuelled by ever-improving sensors, data management, connectivity, and autonomy.

Since committing an initial £2bn towards the programme in 2018 – after France and Germany announced a joint programme a year earlier (joined by Spain in 2020) – the UK government has promised more cash for defence in a security review in March, and Prime Minister Boris Johnson has namechecked Tempest during defence announcements. Tempest, says analysts, is the UK’s bid to stay ahead of the game in the wake of Brexit and foster home-grown talent after the demise of expertise since Typhoon, which will be retired from service.

An updated report commissioned by BAE Systems to rustle up support for the project forecasts the Tempest programme will contribute £26.2bn to the economy from now until 2050 and support 21,000 jobs from 2026 until the middle of the century – and more beyond, say report authors PwC.

Benefits will be felt particularly in north-west England, where the project is expected to generate at least £7.9bn gross value added, and also in Wales and Northern Ireland. As one defence analyst noted, the project’s regional reach would make it difficult for any future government to pull the plug. There’s no official estimate for the cost of the programme; defence analysts (quoted in the Financial Times) have put it around £25bn.

There are opportunities for niche engineering and technology firms beyond traditional aerospace sectors. “I’d encourage all SMEs out there to let us know how you can bring value, how you can help deliver faster and cheaper and boost capability,” said Phil Townley, director of future programmes at Rolls-Royce, at a recent webinar.

While the UK has committed to buying Lockheed Martin’s F-35 fighter jets from the US, it has not benefitted from industrial expertise on home turf. “We’ve been disillusioned by the F-35,” says Francis Tusa, editor of Defence Analysis. “We thought we’d get better and cheaper if we went American – that all turned out to be hogwash. Costs are eye-wateringly high and getting worse.” Originally, the UK was committed to buying 138 F-35s, now cut to 48. “Over the last two years people are looking at our options to replace it or at least to operate alongside.”

Firms behind the project are adamant Tempest will be upgradeable and able to adapt on the fly – and so avoid obsolescence for decades to come.

BAE technologists at Warton in Lancashire are busy road-testing technologies for use within Tempest’s cockpit – which will be virtual, save possibly for a physical throttle and some sort of tactile surface “because you need to do something with your arms”, says Suzy Broadbent, head of human factors shared service at BAE Systems Air.

Broadbent works with the words of a fighter pilot in mind. “He said to me ‘you have to understand – every time I get into a jet, I know I could die’.” Regular tests with a range of pilots across the programme help inform the research, and it’s her job, she says, to build trust in automation and AI.

Levels of automation are inevitably rising, and putting AI in charge of tough decisions makes people understandably queasy. “We’re doing a lot of work to understand which tasks we will want a human to be responsible for,” says Broadbent. While the plane might fly itself, “it’s the human decision-maker traditionally sat in the back – as in a Tornado – that we might need”.

Pilots will see what they need when they need it – such as targets, controls, the horizon – overlaid on the visor of BAE Systems’ Striker II helmet. This is the much-publicised ‘wearable cockpit’ – the original helmet-mounted display has been in use in Typhoon since 2009. Broadbent’s colleagues are currently working out how to make red graphics visible in sunlight; what works in the lab doesn’t always perform well in the real world. Software, she says, will be easy to upgrade. “We’re looking at an app-based system so you don’t have to ground the whole fleet – you can just update the helmet software.”

Her team works with eye-tracking technology – already well established in other industries from automotive to marketing. In the future, pilots could use their gaze in place of physical controls. Eye tracking also helps monitor pilots’ attention during training. But it has another use – pupil size and rapid movement reveal the workload and stress that pilots experience: “This is the psycho-physiological side of our work.”

This is a “game changer” according to Broadbent – being able to glean how overloaded, or distracted, pilots feel at any given stage. Test pilots also wear EEG caps measuring electrical brain activity during tasks to help monitor their cognitive load. Previously pilots assessed themselves after a test, “which is subjective and prone to bias”.

Under stress, she explains, pilots might suffer “attention tunnelling” and miss important signals. “Human error can be a major cause of incidents. It’s a fine balance – you don’t want them overloaded and stressed but you don’t want them bored. Humans aren’t good at vigilance for long periods. In our last trials, we were able to say with 95 per cent accuracy whether someone was in a high or low workload situation.”

Her team are trialling the likes of haptic gloves and suits and 3D audio to give pilots enhanced awareness – a ‘tap’ on the shoulder or an audible warning from the direction of a potential threat for example. “It’s all about being able to react faster.” This means borrowing tech and skills from the world of gaming – and luring the skills of people you wouldn’t normally find in defence, she says.

In the future, the project might need new skills – legal and ethics professionals to regulate AI, graphic designers, software engineers for rapid prototyping and simulations. Staff in BAE labs are set up with gaming technology, and work with VR headsets. “We can mock things up and try them out quickly and we’ve got a simulation team who code in Unity.”

Giving crew what they need to know in the heat of the moment – before they know they need it – relies on the ability to condense mountains of data from sensors and systems into useful information, “so that aircrew can focus on the mission at hand”, says Duncan McCrory, chief engineer future combat air systems at Leonardo. “Specific technologies span radar, electro-optics, electronic warfare, data fusion – we bring that all together.”

In Edinburgh and elsewhere around the UK, engineers at Leonardo – which has experience across Typhoon and Tornado – are working with BAE Systems to accommodate their sensing and communications technology. Managing how radars and sensing will affect the aerodynamics, stability and power of an airframe and working out where to put it is a delicate balance, says McCrory. Conditions on board can be harsh – extreme temperatures, g-loads, mechanical stress, and possible electromagnetic interference.

Leonardo engineers talk about a “fail fast” philosophy within the programme – and won’t give too many details away. While embracing model-driven engineering, including digital twin technology, they’re also working with the RAF’s Rapid Capability Office (RCO) and Doncaster-based 2Excel to trial the technology.

This involves testing next-generation sensing communications and kinetic effect systems on board a flying lab (an adapted Boeing 757) “to gather real-world data, build confidence, de-risk technology and show we can do this”, says McCrory. Last year, a human-machine interface was successfully demonstrated in the cockpit of a Wildcat helicopter to task a semi-autonomous drone to feed back information in real time. “That extends the eyes of the aircrew in the battle space.” A cockpit-based AI could be used to fly a ‘loyal wingman’ drone alongside a crewed fighter.

Will Tempest ultimately be equipped with laser weaponry? In April this year, Italy’s military chief of staff reportedly said directed energy weapons – or ‘laser guns’ – were possible on board Tempest, given the levels of power available. “It’s on the table... but the technology needs to be matured,” says Mark Staniforth, chief systems engineer for missile manufacturer MBDA, which has separately led a ship-borne laser weapon programme (Dragonfire).  

In 2019, MBDA revealed a possible range of weaponry that might make it on board Tempest to operate with ever more precise information on targets. Engineers acting as pilots are taking part in tests and simulations in a lab at the firm’s Stevenage headquarters to assess how they might operate systems and weaponry on a real mission, and fighter jet pilots will be brought in later this year to give their feedback and experience.

The company is also looking at levels of automation onboard and also with ‘loyal wingman’ drones. Liaising with BAE Systems, MBDA is developing a system that will recommend the right tools or weaponry for the job. “We’re using artificial intelligence algorithms and machine learning to run through a number of scenarios,” says Staniforth.

As the entire project moves through conceptual stages, MBDA will adapt weaponry as concepts are adopted or discarded. Working with a project from its inception, says Staniforth, has allowed costs to stay down. “It’s revolutionary that we are working together trying to come up with the best solution through open architecture systems rather than protecting our own boundaries.” This level of adaptability will ultimately give expensive weaponry a longer shelf life, he says.

The missile manufacturer is also developing concepts for a missile to track, target and intercept incoming missiles in high-threat environments.

All these complex systems, electronics and instruments on board create an unprecedented demand for power, possibly more than a megawatt at a platform level. To this end, Rolls-Royce is developing an integrated power system linked with an intelligent power-management system, and has embedded two generators, coupled to a high-pressure and low-pressure rotating shaft respectively. The high-pressure generator also serves as an electrical starter, removing the need for a mechanical or compressed-air starting system. Traditional hydraulic systems are being replaced with electrical actuation.

A gas turbine will remain at the core of Tempest engines, which will run hotter than previous models. More efficient thermal management will be critical, as heat generated by onboard sensors and electronics – potentially three times as high as previously – will be redirected to the engine for cooling. Rolls-Royce is also using materials and additive manufacturing techniques to create denser, lighter components that can withstand higher temperatures.

And it will be stealthy. “We’re looking to ‘hide’ the engine within the aircraft and improve stealth characteristics,” says Conrad Banks, Rolls-Royce chief engineer for Tempest. But this is a challenge, requiring convoluted intakes and exhausts.

Although Tempest is UK-led, the involvement of international partners might ratchet up this year, say lead partners. Last year, Swedish partner Saab announced it would invest £50m in a UK future combat air systems hub after coming on board in 2019. “International by design” is a phrase used by partners, but ultimately Tempest is a project that wants to build UK industrial expertise – and reinvigorate the UK manufacturing and technology sectors.

“It’s going to be good, like nothing that’s gone before,” says Leonardo’s Howard. “Given the sensitivity of the programme, we might fall short of the details we can share, but if people really want to know more, they can find out by joining us.”