Bournemouth Branch 2026 Sir Alan Cobham Lecture: How Alternative Propulsion Changes Aircraft Design, Range and Payload

How do alternative propulsion technologies affect aircraft design, range, payload and operational use, and what constraints are imposed by current technology and fundamental physics? Electrification, hydrogen and other alternative propulsion technologies are widely promoted as the future of aviation, driven by the aim of reducing dependency on traditional hydrocarbon fuels. However, whilst some concepts have shown promise when used in small general aviation aircraft, several programmes have encountered major technical and economic challenges, with some high-profile projects being significantly delayed, scaled back or cancelled.

This lecture examines the engineering realities behind alternative propulsion systems and energy storage technologies. Using first-principles analysis and real-world examples, it explores how different propulsion concepts affect aircraft design, and the resulting impacts on range, payload and operational capability. Physical limitations of current state-of-the-art technologies are quantified using simple engineering principles, drawing where necessary on the laws of aerodynamics and thermodynamics, but without requiring specialist knowledge.

Attendees will gain insights that should enable them to evaluate announcements of new aircraft designs and propulsion concepts from an informed engineering perspective and better understand the trade-offs involved in translating such concepts into practical operational aircraft. The evening will start with a buffet reception at 18:30 to which all are welcome. The lecture will start at 19:30. There will be a collection on the night to support chosen charities.

Speaker: Tim Watkins BEng (Hons) MRAeS MSFTE, Lead Flight Test Engineer at the UK Civil Aviation Authority, with 30 years of aviation experience and 20 years of flight test and certification experience spanning military, civil and remotely piloted aircraft.