 Specifically, instead of having a separate body of regulations for a PMA Fabrication Inspection System (FIS), as was the case in prior regulations, the PMA regulations now include a cross reference to the 14 C.F.R.§ 21.137, which is the regulation defining the elements of a quality system for all production approval holders.In practice, all production approval holders were held to the same production quality standards before the rule change - this will now be more obvious in the FAA's regulations.