Federal safety regulators say they will retain power to approve Boeing 787 airliners for flight rather than return that authority to the aircraft maker, which hasn’t been able to deliver any new Dreamliner planes since last May because of production flaws. The Federal Aviation Administration said it told Boeing of its decision Tuesday. The FAA said that once deliveries of 787s resume, it will perform final inspections and retain power to clear each new plane until it is confident that Boeing’s quality control and manufacturing “consistently produce 787s that meet FAA design standards.” It also said Boeing must have a plan for handling planes that need reworking. “This will allow the agency to confirm the effectiveness of measures Boeing has undertaken to improve the 787 manufacturing process,” the FAA said in a statement. For years, the FAA has relied on Boeing employees to certify the airworthiness of planes by deputizing …