WASHINGTON (Reuters) - Federal Aviation Administration (FAA) chief Steve Dickson said Tuesday the agency is acting quickly to finalize a new emergency airworthiness directive that will require stepped-up inspections of all Boeing 777-200 airplanes with Pratt & Whitney PW400 engines after an engine failure on a United Airlines flight. The agency announced Sunday it would soon issue a directive, while United said it would ground its fleet of 777s with the engine in question pending the FAA directive. “We have been working on this nonstop since Saturday afternoon and I am confident that we will get it right,” Dickson said. “We want to understand what happened and then take the necessary steps to prevent a similar occurrence in the future.” (This story fixes headline from 77 to 777))