Last week saw an astonishing moment of frankness from the A380’s biggest customer. Tim Clark, President of Emirates, told Bloomberg that not only had discussions on a new re-engined A380neo version of Airbus’s 525-seat jet “kind of lapsed,” but that his “main concern is that they stop producing the plane.”

This was the first intimation that sudden death is a possibility for the troubled super jumbo. And the numbers highlight this risk....