CFM, the engine joint venture owned by GE Aerospace and France's Safran, has broadened its technical focus for the next generation of jet propulsion by formally studying a ducted-fan architecture alongside the open-fan concept it has previously championed, industry sources said.
The open-fan approach, which exposes a large fan instead of enclosing it in the traditional casing, has been promoted by the venture within the RISE research programme as the most fuel-efficient route for future Airbus and Boeing widebody and single-aisle families. Under RISE, CFM says the open-bladed concept could yield roughly 20% savings in fuel burn and associated emissions.
Sources told Reuters that CFM is now also investigating a more conventional layout in which the fan is contained within a shroud similar to current engine casings. That alternative design is being studied under a separate internal label identified as "Advanced Ducted-Large" or ADL, according to a Safran job description seen by Reuters and confirmed to exist by three industry sources. The employee's stated responsibilities include work on future civil and defence programmes, naming both the Open Fan and the ADL project.
Industry experts note the trade-offs between the two architectures. Shrouded, ducted fans typically deliver smaller fuel savings compared with exposed open-rotor concepts, but they can offer advantages in terms of adaptability and packaging. The exact performance gap is not restated beyond the RISE figure for the open-fan.
The parallel workstreams matter for more than technology alone. The selection between open-rotor and advanced ducted designs carries potential consequences for the commercial plans of aircraft manufacturers and for which engines airlines and lessors may favor for fleets expected to enter service around 2040.
CFM and its parent companies have publicly maintained that they will supply whatever engines airframers select and have not ruled out more traditional designs even while emphasising the benefits of the open-bladed architecture. The creation of a distinct code name and a visible assignment in a Safran job posting mark the first concrete sign that the ducted option is being treated with dedicated attention inside the venture.
Both Safran and GE declined to comment when approached. The French group is scheduled to report earnings on Friday.
Contextual note - The RISE programme has been referenced in discussions of fuel and emissions reductions for future civil aircraft, and the parallel study of ADL reflects CFM's engineering breadth as it prepares options for airframers and operators.