Airbus is actively encouraging propulsion manufacturers to explore open-rotor engine concepts to offer competition to CFM International’s RISE programme.
Although still a demonstrator, the RISE engine is already attracting Airbus’s interest as it begins working on concepts for an A320neo successor through its Next Generation Single Aisle programme.
Airbus chief executive Guillaume Faury stresses that while Airbus has not yet selected the RISE powerplant, “the open-rotor architecture is a very promising one”.
CFM touts the RISE open-rotor design as offering the potential to cut fuel-burn and emissions by 20% over the latest generation of turbofan engines. The demonstrator will fly first aboard Airbus’s A380 testbed in the second half of this decade.
Airbus has traditionally offered a choice of powerplant suppliers on its narrowbody aircraft: customers for the current A320neo family can select between the CFM Leap-1A or Pratt & Whitney PW1100G geared turbofan (GTF).
But if the RISE engine is picked for a future Airbus single-aisle, offering an alternative will be much more challenging due to the significant installation differences between an open-rotor design and a traditional turbofan.
Faury maintains that Airbus is keen to continue presenting operators with a choice and is pressing other engine suppliers to investigate the open-rotor architecture.
“We would prefer to be able to have open-[fan] offers… from at least one other engine manufacturer, if not more. And that is something we are making clear to the other engine manufacturers,” he tells FlightGlobal.
“If the open-rotor architecture works we would like to be able to compete and potentially have two solutions.”
But with the other two big engine makers, Pratt & Whitney and Rolls-Royce, seemingly wedded to their geared-fan designs – the GTF and UltraFan – it is unclear who else would pursue another open-rotor concept.
Nonetheless, Faury is sanguine if no alternative emerges: “If it’s not the case, it’s not the end of the world – the [Boeing] 737 is a single-aisle with only one engine option… and the A350 has only one engine option and it’s a very successful programme. So that’s something we can live with.”
Airframers have two routes around engine selection, he says, either competing ahead of a programme launch and selecting the best product or allowing the market to choose by offering two or even three choices on the platform.
“So, there are still a lot of possibilities in front of us. We will be wrong to come to conclusions too early,” he adds.
While CFM is invested in the RISE concept, P&W has also outlined a roadmap for the PW1100G. “Pratt considers they have a lot of additional improvement to bring to the GTF to bring it close to what an open-rotor architecture can deliver,” says Faury.
“And we are looking at all those options. Today we have not decided to go for an open-rotor architecture – we are testing this solution.”
