By Rodney MuhumuzaKAMPALA, Uganda -- A Boeing ( BA) 787 operated by Ethiopian Airlines flew from Ethiopia to Kenya's capital Saturday, the first commercial flight since air safety authorities grounded the Dreamliners after incidents with smoldering batteries on two different planes in January. The Boeing 787 passenger jet arrived in Nairobi on Saturday afternoon after a two-hour trip from Ethiopia's capital, Addis Ababa, according to the Kenya airport Web site. The Dreamliner arrived at Nairobi's Jomo Kenyatta International Airport at 12:40 p.m. local time, according to the Kenya Airports Authority. The U.S. Federal Aviation Administration has approved Boeing's redesigned battery system, which the company says sharply reduces the risk of fire. Richard J. Horigan, a Boeing engineer, told reporters in Nairobi this week that all potential causes of battery fire have been eliminated with the new system. But he noted that the root cause of smoldering batteries experienced by the two different 787s may never be known because the evidence was destroyed by heat. "We would like to thank Ethiopian Airlines for the patience, support and leadership shown throughout the period that the 787 Dreamliner has been grounded," Boeing Commercial Airplanes President Ray Conner said in a news release. There are 50 Dreamliners in service around the world. Once the FAA approves the fix on individual planes, airlines can start flying them again. United Airlines ( UAL), the only U.S. airline with the planes, moved one of its six 787s to a Boeing facility in San Antonio, Texas, on Tuesday so it can get the battery fixed. Neither of the battery incidents involved a United jet. Boeing said Wednesday that deliveries of the 787 should resume in early May. ___ Associated Press reporter Gene Johnson in Seattle contributed to this report.