By David Shepardson FAA Administrator Steve Dickson told a U.S. House committee that the agency is “requiring the manufacturers to address strengthen(ing) the cowling.” He also said the agency was working with Boeing and PW to ensure “the structure around the engine, the cowling and the inlet area, does not damage the aircraft structure.” A United Airlines 777 PW400 engine failed shortly after takeoff from Denver on Feb. 20 showering debris over nearby cities, but no one was injured and the plane safely returned to the airport. The FAA in February ordered immediate inspections of 777 planes with PW4000 engines before further flights, after the National Transportation Safety Board found a cracked fan blade on the United engine was consistent with metal fatigue.