where is the mach loop
17. The Mach Loop is a set of valleys, situated between Dolgellau in the north, and Machynlleth in the south (and from which the Mach Loop gets its name), which are regularly used for low level flight training, with flying as low as 250 feet (76 metres) from the nearest terrain.he Ministry of Defence website has a map showing the location of the low fly areas. The Mach Loop is located within LFA7, which covers the whole of Wales, except for a small section in the north-east of Powys, which is within LFA9.