A new definition of sustainable aviation and an accompanying framework for achieving it have emerged from a collaborative effort between aerospace engineering professor Phil Ansell and his student Elias Waddington at The Grainger College of Engineering, University of Illinois Urbana-Champaign. The work originated in Ansell's sustainable aviation course, where he posed a pivotal question: "What does sustainability look like integrated into a system engineering process?"
"Industry, government, and academics have stated sustainability goals, but at times the goals contradict each other. We don't even know how to achieve some of the goals. What we do know is system engineering – a process for designing complex systems," explained Waddington, a Ph.D. student.
Waddington emphasized the need for a holistic perspective, stating, "Sustainable aviation isn't just an environmental issue. If it were, we could just stop flying. Problem solved. But that solution doesn't serve our needs for transportation and commerce."
The pair's newly proposed definition examines sustainable aviation as a comprehensive process. It connects communities while mobilizing people, goods, and services, aiming to minimize harm to human health, enhance quality of life, and conserve natural resources.
"We can't ignore any element. We need to look at how aircraft affect the world, and we need ways to measure those effects," Waddington added.
Framework for Quantifying Sustainability
The framework assigns numerical scores to various aspects of aircraft systems and operations, including technology readiness, operational costs, end-of-life recyclability, and certifiability. Waddington elaborated on the technology readiness scale, explaining that a score of 10 indicates a proven design in active service, while experimental designs like the Airbus ZEROe rate lower due to their developmental stage.
"This framework is meant to show what our perspective on sustainability can do for the analysis of future aircraft. We can look at a design and say it has great environmental potential, but we have a lot of technical and policy challenges associated with it," he said.
To illustrate the concept, Waddington pointed to the Concorde, noting that while it was technically advanced and operationally successful, its high operating costs and limited social impact rendered it unsustainable.
Theoretical Foundations
Waddington credits the book Urban Sustainability in Theory and Practice: Circles of Sustainability by Paul James for inspiring his approach. He adapted James' framework, initially designed to measure urban sustainability, for use in aviation.
"At this stage, it is a way to think about and communicate sustainability, but the details of this analysis are preliminary," Waddington noted, adding that the team is currently measuring sustainability effects across historical and contemporary aircraft.
"Sustainability is like safety," he concluded. "It is not something you can just check a box and be done with. It's a process in the way that we think and interact with the world – and can thrive when adopted as a culture."
Research Report:A definition, conceptual framework, and pathway towards sustainable aviation
