 Here, all 747 and 777 fleet 'heavy' maintenance along with most of the airline's long-haul fleet interior conversions is done.British Airways Avionic Engineering (BAAE) is also based in South Wales which is responsible for the repair, modification and overhaul of the vast majority of the avionic and electrical components used in the BA fleet and some of those used by other airlines.It is situated in three purpose built workshop buildings at Llantrisant.