So what does the future hold for commercial air travel? Carl and Richard chat about the on-going evolution of airliners, starting with the latest generation: the Airbus A380 and the Boeing 787. They represent the pinnacle of traditional airliner design so far. But is it time for a radical break? How can airliners be improved to lower costs, emissions and so on? Richard digs through the on-going evolution in turbofan engines, and looks to the future of more radical engines. Will supersonic flight ever make a comeback? And why stop there, what about hypersonic flight? Nothing is easy, but there's lots to think about!