Developing a new business jet takes years—up to 16 in the case of the recently unveiled (though not yet customer-ready) Gulfstream G400, and only if everything goes smoothly from here on out. Part of that has to do with timing and market positioning—the G400’s larger G500 and G600 siblings, with which the latest plane shares roughly 80 percent common parts, were also conceived in 2009 but certified and delivered in 2018 and 2019, respectively—but it’s
