Pioneering aerodynamic engine testing is powering the development of the UK’s next-generation supersonic stealth combat aircraft, Tempest.

The above image shows Rolls-Royce Tempest engine TDV3/1 intake Integration testing in TP141 testbed, Bristol.

Engineers from leading combat air industry partners, including Rolls-Royce and BAE Systems, are leveraging advanced manufacturing processes to produce uniquely designed engine components that contribute to the aircraft’s stealth capabilities.

The testing phase has seen the production of an engine duct that’s shaped to slow air from supersonic to subsonic speeds at the engine face. This innovative design has resulted in an intake with fewer moving parts than a traditional fighter jet design, thereby enhancing the aircraft’s stealthy design. The tests have been conducted at Rolls-Royce’s site in Filton, Bristol, in the same facility where the Concorde Olympus engine was tested in the 1960s.

Speaking about the testing, Conrad Banks, Chief Engineer at Rolls-Royce Defence Future Programmes, said the aerodynamic testing has “been invaluable in several ways. Not only has it validated complex digital techniques and models, but it has fostered highly collaborative working practices between the BAE Systems and Rolls-Royce teams.

The aerodynamic engine testing is part of the broader Flying Technology Demonstrator programme that was first announced by the UK Government in July 2022. This programme aims to deliver the Tempest, a supersonic stealth combat aircraft set to take flight within the next four years. The development involves experts from BAE Systems, Rolls-Royce, Leonardo UK, MBDA, and the Ministry of Defence (MOD), in collaboration with various British small and medium-sized enterprises.

Richard Berthon, Director Future Combat Air for the MOD, commented on the broader scope of the programme, stating, “The Flying Demonstrator programme is a remarkable effort to design and build a supersonic stealth jet that will prove integration and develop our national skills, while providing data and learning in support of Tempest entering service by 2035.

George Allison
George has a degree in Cyber Security from Glasgow Caledonian University and has a keen interest in naval and cyber security matters and has appeared on national radio and television to discuss current events. George is on Twitter at @geoallison

45 COMMENTS

  1. Interesting looking intake. When I first saw the picture I thought it was the exhaust nozzle! Impressive looking technology.

    However, the really impressive part of this story is the apparent speed of the programme. The Demonstrator sounds to be a predominately a UK effort and probably reaches well back into the early, less well publicised, research phases of the project. Seeing the engine is taking physical form is a big confidence boaster that the demonstrator will actually fly in about 2027 / 28…

    All good news.

    Cheers CR

    • Simliar in a way, but something you do have to develop and test due to the complex aerodynamics involved, the slightest change can snowball into huge changes in drag.

        • Wasnt a drag issue . Plenty of planes have had more powerful engines with larger intakes. F-16 , various marks of the Harrier over the years, come to mind. Its a myth that originated by a prolific UK aviation writer who should have known better
          The actual problem was the civil design Spey was limited by the compressor exit temperature at M2 or so and couldnt go higher . RR could have developed the engine for another £50 mill to gain higher speed – which would never be used, as missiles could go much faster. The Spey used gave higher TO thrust, better mid range acceleration and better fuel economy , all of which were worthwhile.
          Indeed the Spey was in the running to be the installed engine for the USAF fighter-bomber version. But the usual reasons meant it wasnt used by USAF but the USN were more than happy for the non AB Spey in their A-7 upgraded to replace the Pratt engine

    • Well to be fair as Japan committed to Bae and RR completing design for this duct and associated aerodynamic work for their own 6th Gen fighter before combining the programs I assume that it is a pretty complex structure to perfect so worth knowing it’s being tested, as engine efficiency and stealth very much rely on it being perfected. Must admit however I have no idea if a two engine set up and a large single engine set up can work with a similar design of inlet duct.

  2. I’m guessing by the fact they are advertising testing of an engine intake means little else is happening on the engine development, nothing about revolutionary capabilities like high bypass ratio or magnetic engine blades that can produce power.

    • They announced 4 bits of stuff they were testing,

      1. New engine intake design
      2. Martin Baker 16A ejection seat (common with Eurofighter) which they were testing on a rocket sled with a Hawk trainer cockpit and is intended ejector seat and canopy jettison system combo for Tempest.
      3. Safety rated AI software coding with the AI writing the aircrafts flight software.
      4. Aircraft flight simulator with the intended cockpit layout and controls which 10 pilots have logged approx. 150 hours in.
    • I’d probably expect the Tempest demonstrator to fly with EJ200’s in the back. Much like EAP was fitted with RB199’s.

      • I would expect so, as the late great Roland Beaumont used to say, a new prototype should always fly with known engines….

    • Well to be fair they are making, testing and promoting rather innovative design aspects or newgen engines altogether, be it from the Pearl project, through the B52 upgrade related product to their carbon fibre and Titanium bladed new Ultra Fan engine. So plenty of development going on. However even though much initial work on the Tempest engine seems to be underway until the aircraft it is to be used on is better visualised it’s unlikely the final design for it as a complete unit is presently being built. The demonstrator will I suspect fly initially on Typhoon EJ engines modified or otherwise while aspects of its true engine are tested and finally combined somewhat later no doubt influenced by its various other programmes already in existence. They are in the process of transforming their whole range at the moment that will start to be introduced over the next few years and I’m sure much of that (and certainly lessons from it) will feed into its military business too. They have already defined an engine concept last year to supply the extra power that Tempest will require and the Ultra Fan specifically increases the high bypass element as an integral design factor of the new engine, so clearly whatever concept is deemed best suited to a military engine it’s not a concept they are not already actively involved with and improving upon.

    • This latest show-and-tell event is about the work on a UK-only demonstrator aircraft, not about the final aircraft developed with the partners. The UK demonstrator will apparently use EJ2000, so there’s no need for them to talk about the engine being designed for the final aircraft.

      The final engine on Tempest will very likely be a joint development, particularly between Rolls Royce and IHI. Work on a joint engine demonstrator was announced over a year ago. I expect they are still deep in negotiations about how the engine will be developed.

    • high bypass ratio “

      This is impossible idea for a fast jet with AB . Normal BPR might be 1.2 not the numbers used for civil planes like A320 and B737 with 11- and the diameter to match!

  3. I hope, like Concorde, the Tempest winds up being able to “super-cruise.” i.e. able to cruise at supersonic speeds without use of afterburner once it is up to speed. Also it does not wind up like the Lightning with only 12 minutes of full power, or the F35B with such a limited combat radius. In-Flight thrust vectoring may also be a must-have.

    • Supercruise isn’t all its cracked up to be. Because it uses a lot of fuel. For short periods its good for putting more energy into your missile shots, effectively giving the missile a head start, increasing launch range. F35B has pretty good endurance, it carries more fuel than a Typhoon. Thrust vectoring also probably won’t be a part of Tempest. Range, payload and stealth will trump super maneuverability.

    • I can’t believe it won’t have Super-cruise, that does seem like a necessity and indeed (though it’s rather nebulous) is generally stated as a must have to be considered a 6th Gen fighter. Thrust vectoring I am not so sure about, the YF-23 was nearly as acrobatic as the YF-22 despite not having it and saving on the weight and complexity gave it other advantages which are arguably much more beneficial. Considering the work done already for the Typhoon/EJ-200, would make it an option for Tempest if they saw it as advantageous I presume. It will be interesting to see if the US persists with it or indeed anyone else. Looks good at Airshows mind.

      • I mean, f-35 doesn’t have supercruise at the moment. I think GE is developing a new engine for the f-35 to enable this.

        • I understood that f35b can supercruise, ie fly at supersonic speed without afterburner, but it needs afterburner to get it supersonic. Typhoon can supercruise without ever using afterburner.

  4. want this to be successful but can anyone explain the advantage of being able to pilot tempest and also have unmanned tempest, having both capabilities appear to have negative consequences.

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