The 61st Fighter Squadron (61 FS) is an active United States Air Force unit, assigned to the 56th Operations Group, at Luke Air Force Base, Arizona. It operates the F-35 Lightning II aircraft, conducting Instructor Pilot training. The 61 FS, known as the ‘Top Dogs’, fly F-35A aircraft, to train instructor pilots and initial qualification pilots for Air Combat Command assignments. This patch does not come with velcro attached.