An Ethiopian Airlines 787 Dreamliner has flown from Addis Ababa to Nairobi, the first commercial flight by the Boeing aircraft since all 787s were grounded in January.
The 50 planes around the world were grounded due to battery malfunctions that saw one 787 catch fire in the US.
Over the past week teams of Boeing engineers have been fitting new batteries to the aircraft.
This was after aviation authorities approved the revamped battery design.
The Ethiopian Airlines plane took off at 09:45 local time (07:45 GMT) and landed in Nairobi, Kenya, some two hours later.
Each 787 has two of the lithium-ion batteries which caused problems.
In addition to new versions of the batteries which run at a much cooler temperature, the batteries are now enclosed in stainless steel boxes.
These boxes have a ventilation pipe that goes directly to the outside of the plane. Boeing says this means than in the unlikely event of any future fire or smoke, it would not affect the rest of the aircraft.