The roar of the wind crescendos with the airplane engine as the runway recedes into a long, gray ribbon stretching behind 19-year-old Zara Rutherford. She was taking her first test flight in the aircraft she will pilot around the world. At the moment the wheels of the Shark Ultralight lift off the ground, a massive grin splits the teen's face nearly in half. She is right where she wants to be. Raised in a family of pilots, Rutherford, who is Belgian and British, started flying at a young age. “I went to school in Belgium and England and have been...