A cool video of F-15s flying low and fast in the Mach Loop North Wales. The F-15s are from the 492nd Fighter Squadron (492nd FS), nicknamed “The Madhatters” based at RAF Lakenheath. The Mach Loop is a set of valleys, between Dolgellau in the north, and Machynlleth in the south, used for low level flight training. Be sure to watch F-35 Lightning II Low Level to see more awesome scenes of fighter pilots training.