Comment: Hybridisation is a new era for aerospace

The aerospace industry is under immense pressure to achieve net-zero emissions by 2050. One of the most promising solutions lies in hybrid-electric propulsion, integrating electric power with traditional or modified combustion engines to enhance fuel efficiency, reduce emissions, and optimise fuel consumption.

While fully electric aircraft face limitations due to the current battery technology’s energy density, hybrid systems offer a practical bridge to sustainable aviation, combining the environmental benefits of electric power with the operational flexibility and range of traditional aircraft.

Why hybridise the aerospace industry?

Hybrid systems optimise energy usage by leveraging electric power during high-demand phases of flight (such as take-off and climb) and recharging during cruise or descent. This not only improves fuel efficiency but also reduces emissions, offering significant environmental, operational, and economic benefits. Additionally, hybrid systems open the door to the growing Urban Air Mobility (UAM) market by enabling quieter electric vertical take-off and landing vehicles (eVTOLs), a critical advantage over conventional rotorcraft like helicopters.

The pathway to hybrid adoption

For hybrid-electric propulsion to become widespread, we must overcome several technological and regulatory challenges. Ensuring seamless energy transfer between electric and conventional propulsion systems bring unique technical challenges.

Battery technology must evolve to become lighter, more durable, and capable of faster charging, while the integration of power and thermal management systems across different propulsion types must be optimised for maximum efficiency. Nevertheless, current certification standards may not be sufficient to address the risks posed by this novel technology, requiring the development of new standards.

So, how can we address these complex challenges?

1. Advanced simulation and testing

The electrification of aircraft depends heavily on complex electronics and advanced materials, demanding rigorous safety testing and verification. While advanced electronics can sometimes lead to increased electromagnetic emissions, modern design practices and improved components, such as active filtering and enhanced shielding, mitigate these risks, ensuring high system efficiency without compromising electromagnetic compatibility (EMC).

Advanced simulation tools are critical to predicting and managing potential risks, optimising power and thermal management, and meeting aerospace safety standards. These innovations will be essential to ensure the safe, reliable operation of future hybrid-electric aircraft.

2. Start with smaller aircraft and short-haul flights

Although hybrid-electric propulsion offers great promise for sustainable aviation, the scale-up to larger aircraft remains a challenge. Liquid hydrogen, for example, would require heavy, complex storage systems at cryogenic temperatures for long-haul flights, and the infrastructure at airports to support such systems is lacking. Additionally, hydrogen production is still largely derived from non-renewable sources, limiting its environmental benefits.

Focusing initially on smaller aircraft and short-haul flights allows for controlled testing and optimisation of various hybrid-electric systems. This incremental approach provides a proving ground for technology, offering insights that can be leveraged to scale up for larger platforms in the future.

3. Collaboration with regulators and industry partners

Key regulatory bodies, such as the Federal Aviation Administration (FAA) and the UK Civil Aviation Authority (CAA), play a central role in shaping the safety and effectiveness of aviation systems. As commercial hybrid-electric operations are expected to begin within the next five years, close collaboration with these agencies will be critical to ensuring that standards for certification, testing, and infrastructure development are clear and timely.

Collaborative efforts with trusted engineering technology partners are equally essential for developing solutions that address the complex needs of hybrid-electric propulsion. These partnerships bring specialised knowledge, speed, and flexibility, leveraging multidisciplinary teams to design, test, and verify integrated powertrains with fail-safe mechanisms and redundancy systems, all optimised through simulation and advanced engineering tools.

The future of hybrid aircraft

Advanced Air Mobility (AAM) is the next frontier in transportation, enabling faster, cleaner, and faster movement of people and goods. While the road ahead is complex, hybrid-electric aircraft will play a crucial role in this evolution, helping to deliver sustainable, high-performance aviation systems.

Dr Julio Coroado, business development, Aerospace Electrified Propulsion Systems at Drive System Design (DSD)