Inside JetZero's cavernous 275,000-square-foot hangar at Long Beach Airport in L.A. County, the future of flight takes an unexpected shape. I run my hand along the carbon fiber surface stitched with Kevlar that will form the aircraft's frame, sit in a passenger cabin mockup built inside what would normally be the wing, and walk through a diagram-filled room where engineers are reimagining everything from baggage handling to boarding procedures. Unlike the cylindrical body of most planes, the