The Boeing 777X's folding wingtips are one of the aircraft's most innovative design features.

This is the original flying wing, the Horten 229. As BBC Future noted in 2016, the ‘flying wing’ design is not a common sight in the skies because it’s an incredibly hard concept to make work.

Today, aircraft wings are increasingly designed to prioritize stealth characteristics over raw speed—giving them a smooth, unbroken connection to the aircraft’s main fuselage. The wing of a fighter ...