Aviation is a poster child for economic stagnation. Yes, airline travel has gotten cheaper and safer—great. But every other aspect of aviation has struggled or even regressed. As I’ve noted many times, we had supersonic travel across the Atlantic from 1976 to 2003. Today, not even the world’s richest travelers can fly that fast.Another part of aviation that has suffered over the last half-century is general aviation, particularly its low-end segment, personal aviation, in which people fly themse...