Boeing 787 airships were grounded a few weeks ago following the discovery of problem in the aircraft's battery system. In the first year of its service, at least four 787s were reported to have problem with the onboard electrical systems, especially with the li-ion (lithium-ion) batteries. After an event of fire in the system in the Nippon Airways at Boston's Logan International Airport, the FAA (Federal Aviation Administration) decided to ground all the 787s that were in operation. The problem was found to be the thermal runaway events during the 100,000 flight hours, which is quite larger than the 10 million flight hours Boeing had predicted.
Boing immediately began inspection and it was reported by the company that the severity of the problem didn't exceed what they were expecting. The FAA had announced a thorough review of the 787's all critical systems including the overall aircraft design, electrical systems, assembly etc.
On April 5, Boeing officially announced that it's fixed the problems with the electrical systems and has obtained certification from the FAA after demonstrating the new battery & electrical systems. The purpose of the certification demonstration was to show that the new battery system in 787 performed as intended during normal and non-normal flight conditions.
Source & Image Credit: Boeing