PHARES - A Clean Aviation Project

Advancing hybrid electric regional aircraft

Quicklinks: About PHARES | Key figures | Objectives | Clean Aviation UERA| Consortium

About PHARES

The PHARES project is advancing the future of regional aviation by developing and demonstrating an innovative hybrid-electric propulsion system under Clean Aviation’s Ultra-Efficient Regional Aircraft thrust. The goal is to achieve readiness for entry into service by 2035. This groundbreaking system combines a state-of-the-art thermal engine based on Pratt & Whitney Canada’s PW127 turboprop engine family, with a Collins Aerospace electric motor, power controller, and an optimized propellor. Together, these innovations aim to deliver up to 20% improved fuel efficiency compared to the 2020 baseline, supporting Clean Aviation’s ambitious target of a 30% improvement in fuel efficiency and reduced CO₂ emissions.

Beyond its efficiency improvements, PHARES is designed to support compatibility with 100% sustainable aviation fuel (SAF) specifications, reinforcing its commitment to sustainability. The project will culminate in a propulsion system ground demonstration, laying the foundation for flight demonstration in the Clean Aviation DEMETRA project. By pushing the boundaries of hybrid-electric technology, PHARES is shaping a cleaner, more efficient future for regional aviation.

Regional turboprop aircraft.
Credit : ATR

Key figures

Target ground demonstration of hybrid-electric engine

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Enable readiness for entry into service

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Improved fuel efficiency, compared to 2020 baseline

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Partners in 7 countries

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Budget with an Clean Aviation contribution of € 69.0 million

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Clean Aviation project coordinated by a Canadian company,
Pratt & Whitney Canada

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SAF compatibility by design

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Explore the PHARES Propulsion System

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PHARES engine with Collins Aerospace electric motor, power controller, and propeller.

Objectives

Design and develop an overall hybrid-electric architecture

PHARES will develop and demonstrate a hybrid-electric engine architecture for the regional aircraft, combining advanced turboprop with 250kW electric motor, power controller, and thermal management systems.

Demonstrate an advanced thermal engine for improved fuel efficiency and 100% SAF compatibility

PHARES will improve overall thermal efficiency of the baseline PW127M turboprop engine (2020 baseline) contributing to reduced fuel burn while maintaining regional aviation segment economics and proven reliability. It will ensure readiness for compatibility with future specifications of 100% SAF.

Demonstrate advanced propeller technologies for higher propulsive efficiency and lower noise

PHARES will mature major propeller components and control system advanced technologies to TRL5 at integrated powerplant level. This will be accomplished via Collins Aerospace Ratier-Figeac internal analysis, simulations and testing activities.

Develop physical integration and aerodynamic optimisation of pylon and nacelle

The targeted hybrid-electric systems drive the need for a dedicated pylon and nacelle, coordinated with the related DEMETRA and HERACLES projects to ensure flight test readiness and to meet flight safety requirements.

Develop and mature key enabling technologies for hybrid-electric system integration and ground test preparation

PHARES will develop and validate sub-systems and enabling technologies to support hybrid-electric propulsion system integration. Activities will focus on technology maturation and preparing for integrated ground testing.

Demonstrate PHARES system maturity through integrated testing and progress toward flight test readiness by 2029

PHARES will demonstrate system maturity through coordinated rig, component, and full-system testing. This includes sea-level test cell and full aircraft ground testing, enabling advancement toward the 2029 flight test milestone within the DEMETRA project.

Clean Aviation UERA

PHARES is one of four inter-related Clean Aviation projects dedicated to developing technologies for the next generation of Ultra-Efficient Regional Aircraft (UERA), with the goal of achieving readiness for entry into service by 2035.

While PHARES is dedicated to developing and demonstrating a hybrid-electric propulsion system, the OSYRYS project will focus on power management and distribution systems for enabling a more electric aircraft architecture. Systems demonstrated under PHARES and OSYRYS will be integrated on an ATR 72 flight demonstrator platform, as part of the DEMETRA project.

Learnings and results from each of these three demonstrator projects will feed into a parallel project, HERACLES, which is intended to refine the design of future UERA concept aircraft. This will incorporate hybrid-electric propulsion, advanced propeller, and more electric aircraft systems, as well as aerodynamic optimizations to the airframe, to achieve Clean Aviation’s ultimate goal of a 30% fuel efficiency improvement for a typical regional aircraft mission, compared to a 2020 baseline.

Related Projects

DEMETRA | HERACLES | OSYRYS

Canada – EU collaboration

PHARES, led by Pratt & Whitney Canada, is the first Clean Aviation project coordinated by a Canadian company, since Canada and European Union entered an association agreement on Horizon Europe in 2024. The project is a significant step in the long-standing collaboration between Canada and Europe’s aerospace industries, which will help accelerate the demonstration and entry into service for of advanced technologies of next-generation aircraft.

The project brings together a transatlantic consortium of key industrial partners, including Collins Aerospace and ATR, alongside European suppliers and research organizations. With contributions from France, Italy, Poland, and the United Kingdom, PHARES showcases a collaborative approach to advancing propulsion, electrical systems, and aircraft integration.