Haydn
Ad fpe 6a7 used to be the document that was required. This ad was cancelled in 2011 whith a few extras. These ads set the stardards but now we are left with the mess we have now which in part was set by aopa.
Manufacturers not just for fire extinguishers can and do set there own periods of maintenance. This however is over ridden by the Airframe manufacture. However if the airframe manufacture has not addressed the component then the component manufactures maintenance and o/h periods MUST BE USED.