Systems, methods, and apparatus for ultra-sonic inspection of a surface are described. An example system may include an inspection robot structured to move in a direction of travel on an inspection surface. The inspection robot may include a payload including a first ultrasonic (UT) phased array and a second UT phased array, the first UT phased array and the second UT phased array being arranged in a parallel configuration. The inspection robot may include a rastering device structured to move the payload in a direction of inspection, the direction of inspection being distinct from the direction of travel and the direction of inspection being distinct from the parallel configuration of the first UT phased array and the second UT phased array.