US Army

The headline says printed engine, but one of the reports calls it only partly made additively, and none says which parts. For a European engine or drone supplier, that distinction matters most. Printing used to shorten design loops is a development tool. Printing that stays in flying hardware is a qualification commitment, with military airworthiness rules attached. In an air-cooled rotary engine, the housings take repeated thermal cycling, and in my experience fatigue on as-built surfaces is where printed metal parts often fall short of datasheet values. Before treating this as a template, I would ask which components stay printed in the design meant for series, in which alloy and heat treatment condition, and with what fatigue evidence. Until the design stops changing, buying fast iterations from a qualified metal service provider usually makes more sense than buying a machine.