Airlines, it turns out, prefer the fuel efficiency of smaller planes like the Boeing 777 to the pack-em-in capacity of the Airbus A380. As a result, Airbus hasn’t scored any new orders for an A380 in more than a year. Its big plan to turn things around? Launch a new version, make it cheaper to fly, and slap on some winglets. This week at the Paris Air Show, Airbus announced the revamped “A380plus,” a refresh that packs even more passengers into the super-jumbo and tweaks the wing design. The upswept winglets found on most modern airliners boost fuel efficiency by...