There are 50 787 Dreamliners in service, but they have all been grounded since mid-January after two fires associated with the plane's lithium-ion batteries.
The Federal Aviation Administration Thursday authorized renewed flights based on Boeing's retrofit of the battery system, which includes containing the batteries in a steel box, using a ventilation system to control fumes or smoke, and using a different style of lithium-ion battery that runs at a cooler temperature.
The batteries are not used in flight. They are used for lights and braking when the plane is on the ground, the BBC said.
The return to commercial flight took place with an Ethiopian Airlines hop from the Ethiopian capital of Addis Ababa to Nairobi, Kenya, a 2-hour flight that landed without incident.