The project scope is therefore to design, demonstrate, and deliver the fully integrated hybrid-electric propulsion system needed for a full-scale in-fight demonstration, including:

• The overall propulsive system architecture, capable of achieving the performance targets detailed in next section and based on a parallel hybrid architecture compatible with an FTD platform with 2 wing-mounted engines.
• A high-efficiency thermal engine, compatible with 100% SAF, and benefiting from the optimization enabled by the electrical hybridisation.
• An electric motor/generator, making use of electrical power delivered from a battery.
• An advanced propeller, and the associated mechanical systems to couple the thermal and electrical power to the propeller.
• A nacelle integrating the hybrid powerplant and all nacelle related systems into aerodynamic lines, including optimized intakes and exhaust, and maximizing weight & drag reduction.
• All associated systems/equipment located within the nacelle, including:
  • power conversion and distribution systems, considering High Voltage DC (HVDC) technology;
  • compatiblility with the interfaces of electrical systems and battery storage system installed on the airframe for the FTD;
  • hybrid control and protection system including full thermal/electric power management;
  • thermal management for the entire propulsion system and its nacelle & pylon;
  • a pylon box, fairings, and mounting system hosting the novel hybrid propulsion system, and providing all needed mechanical and systems interfaces with the airframe and on-boardsystems of the FTD platform, ensuring optimised installation and integration features.

Performance Targets: A number of top-level goals for the Ultra-Efficient Regional Aircraft concept will be the basis for performance targets, in particular:

• Contribute to 30% CO2 emission reduction for the ultra-efficient Regional aircraft concept, without the inclusion of 100% SAF fuels, and to 86% CO2 reductions when 100% SAF is considered (assuming an 80% carbon footprint of SAF on average). This KPI is based on 2020 state-of-the-art technologies, paving the ground towards CO2-neutral aviation by 2050.
• To achieve this:
  • a 20% or greater CO2 emission reduction (without SAF) is expected for the propulsion system, when integrated at aircraft level. This number accounts for weight and aerodynamic effects of the propulsive system, hence the weight and size of the overall propulsion system is to be minimized to achieve the highest power density possible without compromising aircraft performance.
  • 100% drop-in SAF compatibility shall be ensured;
  • the evaluation, monitoring and reporting of key parameters needed to assess non-CO2 effects (including NOx, water and non volatile Particulate Matter emissions), to ensure compliance with foreseen regulations and standards for a 2035 EIS;
  • noise emissions levels fully compliant with ICAO noise standard (chapter 14 noise limits), with adequate certification cumulative noise level margin, while considering future updates to the noise standard in view of a 2035 EIS;
  • targets must be compatible with safety as an overarching requirement, and consistent with the certification path, including the CRL objectives (refer to topic conditions and expected outcomes).

The top-level goals shall be broken down in a consistent manner at the different levels: from top-level aircraft requirements to propulsive system, sub-systems and components level requirements.

Proposals shall include a detailed project plan with key milestones and deliverables, together with a list of performance targets per critical technology.