GKN Aerospace Advances Hybrid-Electric Aviation with EU SWITCH Project

GKN Aerospace Delivers High-Voltage EWIS for SWITCH Project: A Leap Toward Sustainable Aviation

The aviation industry stands at a critical juncture, facing mounting pressure to reduce its environmental footprint while maintaining operational efficiency and safety. In this context, the recent delivery of a high-voltage Electrical Wiring Interconnection System (EWIS) by GKN Aerospace for the European Union’s Clean Aviation SWITCH project marks a significant technological and environmental milestone. This development supports the transition toward hybrid-electric propulsion, aligning with the EU’s broader goal of achieving climate-neutral aviation by 2050.

GKN’s EWIS, developed at its Papendrecht facility, is designed to transmit megawatt-class electrical power, a necessity for hybrid propulsion systems. The SWITCH project integrates dual-spool hybrid-electric architecture and water-enhanced turbofan (WET) technology, aiming to improve energy efficiency by 25% and reduce climate impact by 75% when using net-zero CO₂ sustainable aviation fuels (SAFs). Backed by a €1.7 billion EU investment, this initiative is a cornerstone of Europe’s clean aviation roadmap.

Technological Innovations in High-Voltage EWIS

Next-Generation Materials and Design

GKN Aerospace’s EWIS incorporates several first-in-industry features that address the stringent requirements of hybrid-electric aircraft. The harness systems utilize graphene-doped insulation, which offers 30% better thermal conductivity compared to traditional PTFE materials. This improvement is crucial for maintaining system integrity in high-temperature zones near engines, where temperatures can exceed 300°C.

Another innovation lies in the use of shape-memory polymers for dynamic cable management. These materials allow conduits to auto-adjust in response to thermal expansion, ensuring consistent cable tension and reducing mechanical stress on connectors. Anti-vibration mounts further stabilize the system during high-G moments such as takeoff and climb.

On the monitoring front, each harness includes a distributed temperature sensing grid with over 1,000 fiber optic sensors. These sensors provide real-time thermal maps, enabling predictive maintenance and early detection of hotspots. Additionally, the system features partial discharge detection capable of identifying arc precursors at sensitivity levels below 10 picoCoulombs.

“Our Trollhättan test rig’s 20MW capacity enables simultaneous validation of thermal and electrical loads, a prerequisite for megawatt-class EWIS.” , Henrik Runnemalm, VP, GKN Aerospace

Challenges in Certification and Integration

Developing a high-voltage EWIS for aviation is not without its challenges. One of the primary hurdles is partial discharge mitigation. The system must handle sub-nanosecond voltage rise times, with dV/dt rates exceeding 10kV/μs. To combat this, GKN employs nitrogen-filled conduit cavities and self-healing dielectrics that can repair minor insulation breaches autonomously.

Thermal management is another critical area. The EWIS uses a two-phase evaporative cooling system capable of removing up to 5kW per meter of heat load. Directional heat pipes conduct up to 150W/cm² from high-current lugs, ensuring that thermal stresses do not compromise performance or safety.

Electromagnetic compatibility (EMC) is addressed through triple-shielded twisted pairs and common-mode chokes. These components help achieve signal attenuation of up to 100dB at 1GHz and reduce leakage currents to below 1mA, which is essential for maintaining avionics reliability in megawatt-scale systems.

The SWITCH Project: Architecture and Industry Impact

Hybrid-Electric Propulsion System

The SWITCH project’s propulsion system integrates three key technologies: a dual-spool hybrid configuration, a water-enhanced turbofan (WET), and a high-voltage power distribution network. The high-pressure spool includes a 500kW derated motor generator, while the low-pressure spool features a 1MW primary motor. Together, these components support electric taxiing, takeoff boost, and waste heat recovery, capturing up to 40% of thermal energy from exhaust gases.

The WET system recycles up to 70% of combustion byproduct water, reinjecting it into the combustion chamber to cool the flame and reduce NOx emissions by 50%. Additionally, particle filtration within the WET architecture reduces contrail formation by 75%, addressing another significant contributor to aviation’s climate impact.

The electrical backbone operates at 1,200V DC, which is 50% lighter than equivalent AC systems. Solid-state protection mechanisms using silicon carbide (SiC) switches offer microsecond-range fault isolation, enhancing safety and reliability.

Performance Targets and Timeline

The SWITCH project is structured around a phased validation approach. Ground testing of the integrated EWIS began in 2025 at Collins Aerospace’s Grid facility. The project aims to achieve Technology Readiness Level (TRL) 4 for the WET engine and TRL 5 for the Electrical Aircraft Propulsion (EAP) system by 2025. Flight tests on modified Airbus A320neo platforms are planned for 2030, with entry into service for short- and medium-haul aircraft targeted for 2035.

Key performance metrics include a 25% improvement in fuel efficiency and a 75% reduction in climate impact when using net-zero CO₂ SAFs. These figures represent a significant leap from current baselines and position SWITCH as a leader in sustainable aviation innovation.

Such ambitious targets require robust cross-industry collaboration. Partners like MTU Aero Engines, Airbus, and Collins Aerospace contribute expertise in propulsion, integration, and power electronics, creating a synergistic environment for rapid technological advancement.

“SWITCH technologies could eliminate 850 million tons of CO₂ by 2050, equivalent to 2% of global aviation emissions.” , Sabine Klauke, CTO, Airbus

Conclusion: Toward a Climate-Neutral Future

The delivery of GKN Aerospace’s high-voltage EWIS for the SWITCH project is more than a technical achievement, it’s a roadmap toward climate-neutral aviation. By enabling megawatt-class power transmission with reduced weight and enhanced safety, this innovation supports the viability of hybrid-electric aircraft for commercial use by 2035.

However, the path forward is complex. Achieving net-zero aviation will require parallel developments in sustainable aviation fuels, hydrogen infrastructure, and recycling of high-voltage components. Continued collaboration between OEMs, regulators, and suppliers, supported by EU funding and international standards, will be essential to realizing these goals.

FAQ

What is EWIS and why is it important?
EWIS stands for Electrical Wiring Interconnection System. It is critical for power distribution, data transmission, and system control in aircraft. In hybrid-electric systems, EWIS must handle higher voltages and power levels, making innovation in this area essential for future aviation.

What makes GKN’s high-voltage EWIS unique?
GKN’s EWIS features graphene-doped insulation, shape-memory polymers, and advanced thermal and electromagnetic shielding. These innovations allow it to handle megawatt-class power while maintaining safety and reliability.

When will hybrid-electric aircraft using SWITCH technology enter service?
According to the SWITCH project timeline, hybrid-electric aircraft are expected to enter commercial service by 2035, with flight testing on modified Airbus A320neo platforms beginning in 2030.

Sources: GKN Aerospace, CORDIS, FAA, Airbus, Collins Aerospace, MTU Aero Engines, Pratt & Whitney Canada