United Airlines became the first North American carrier to operate the Boeing 737 Max 9 aircraft on Thursday morning, with its inaugural flight departing Houston's Bush Intercontinental Airport for Orlando, Fla. The new planes are more fuel efficient, with the ability to fly farther on less fuel, and provide a quieter ride. Having a longer range than previous 737 models allows United to operate the 737 Max 9 between Houston and Anchorage, Alaska, which previously needed a larger aircraft. The Max 9 is scheduled to fly between Houston and Anchorage on Thursday. It's also scheduled to fly to Austin. United...