At nineteen thousand feet The propeller is 2 metres of Continuous diaphanous blade, A thin curtain of spin slicing the air, There’s a blur at the tip where Contrary paint hints at a solid Fugal edge, the fleeing, flight edge. It would not warn a bird. Held by the engineered centre By its core and cone. This centre can hold, This gyre not fly off. The propeller lives by refinement And human purposes. They are not replaced by the jet. While it looks like nothing’s there “Beware, beware.” The cutting air. Ivan Head