UltraFan advances on two fronts as Rolls-Royce readies for renewed test campaign

Propulsion specialist plans latest tests of widebody engine later this year, with smaller 30,000lbf-thrust variant to arrive in 2028.

Rolls-Royce has begun building up its widebody-sized UltraFan 80 demonstrator ahead of a return to ground testing later this year, while continuing to advance the design of the smaller UltraFan 30 towards a first-run target in 2028.

Although the 85,000lbf (380kN)-thrust UltraFan accumulated around 70h of run time during its initial test campaign in 2023, the return to the testbed is critical to further mature the architecture and supporting technologies.

Briefing journalists at its Derby, UK headquarters on 2 July, Jeremy Hughes, head of demonstrator programmes, said the widebody engine is now in assembly, with the power gearbox recently married to the core.

“The fan case will go on [next] and then that will go back into Testbed 80 before the end of the year.

“That will allow us to demonstrate and derisk both the architecture of the UltraFan concept and the technology.”

Hughes says the UltraFan team has made a several “modifications and changes and improvements” to the demonstrator’s core to address findings from the initial campaign.

In addition to evaluating these updates, the next round of testing is design to “further derisk primarily the architecture”, he says.

“It’s a new centreline [engine] that introduces some fairly significant changes through the LP [low-pressure] system.

“So we’ll go back to test and we will learn significantly about not only what their performance is, but the robustness and durability of them too.”

Meanwhile, work continues on the design of the 30,000lbf UltraFan 30, scaling the geared architecture down to an engine suitable for future narrowbody applications.

Hughes says the concept review for the powerplant was completed in June, advancing a design that Rolls-Royce showcased in March.

“Things are looking very positive, and we are quietly getting on with turning the ideas into hardware,” he says.

“We are aligning our strategic suppliers, we are aligning the wider supply chain, and we are going to have metal available to allow us to complete the build and start testing that concept in 2028.”

Although the UltraFan 30 demonstrator will be based around the core of an existing Pearl business jet engine, development of a more advanced hot section continues, “and long term we see a route to integrating that into the programme”, says Hughes.

This could see a further evolution of the Advance 2 core from which the latest-generation Pearl engines are derived: “That is something we are now heavilly thinking [about] at the moment,” he adds.

But there are challenges to shrinking the technology down to narrowbody size, notably around the power gearbox.

Rolls-Royce has embarked on a “big piece of work” towards that goal, he says, with significant test activity running through late 2026 and into 2027.

In addition, the propulsion specialist is also examining the requirements for the supply chain to ensure it can cope with the high production volumes seen in the narrowbody sector, says Hughes.

The UltraFan 30 introduces several features, such as a short inlet and ripple-edged outlet guide vanes, not yet present on its sister demonstrator.

But Hughes says the company sees “an opportunity for those things to read across” to the UltraFan 80 based on the results of earlier trials of the short-inlet design, including flight tests, conducted with Boeing.

“We feel confident that style of technology reads across market sectors,” he adds.

Additional rig tests are also under way, he adds. One, located at the joint German-Dutch windtunnel facility in Marknesse, is examining fan aerodynamics when coupled with the inet, while a second, in Darmstadt, Germany, is exploring the aero-mechanics of the fan.

Hughes says the company has an ambition to take the UltraFan to flight test, a key requirement if it is to demonstrate the engine has reached technology readiness level 6.

Although he says the flight-test platform has not yet been defined “there are a number of options available to us and we are exploring those”.

“We don’t think we need to make that decision at this point in time but clearly we will worrk towards it.”

However, the path to UltraFan 30 development and industrialisation is not yet clear, says Rob Watson, president of Rolls-Royce’s civil aerospace unit.

It continues to explore a range of partnership options “and we are thinking very creatively about what the right partnership could look like”, he says.

While a partnership remains the prefered approach, “if we had to do that alone, OK”, says Watson, referencing recent media statements from Rolls-Royce chief executive Tufan Erginbilgic.

To gain a position in the narrowbody market will require Rolls-Royce to break the current CFM International-Pratt & Whitney duopoly when Airbus and Boeing commit to their next-generation single-aisles at some point around the turn of the decade.

In the widebody segment, however, where no manufacturer has a stranglehold on engine supply, the route to adoption is simpler.

Although there have been suggestions the UltraFan 80 could be used to re-engine an existing platform, Watson thinks this scenario is less likely.

“Our view is that the step-change in technology, the step-change in performance, probably warrants a new aircraft.

“We’ll have to wait and see, but of course we are talking to both platformers around what the options could look like,” he says.