Navy Undersecretary Sean Stackley told House members yesterday that the Navy would continue to see gaps in aircraft carrier deployments until the number of carriers returned to the 11 mandated by law. 5 more images in gallery .related-stories { display: none !important; } The aircraft carrier "is at the very core of our maritime strategy," US Navy Assistant Secretary of the Navy for Research, Development and Acquisition Sean Stackley told the House Seapower and Projection Forces subcommittee on Tuesday.