A somewhat confusing issue here is whose rules apply. The order is this. The Aircraft Manufacturer over-rules everyone. If procedures are setup for testing any of these systems by the Aircraft Manufacturer, they take precedence. Examples are pitot static systems, RVSM tolerances, or ADC performance testing. If the Aircraft Manufacturer has not covered the ground in published procedures, then the Appliance Manufacturer's procedures take precedence. Examples of this are Air Data Computers. Both Honeywell-Sperry and Rockwell-Collins have procedures for recertification of their ADC's on the aircraft, and so save you considerable money and time if you have the test equipment to accomplish it. Lastly, the requirements of the FAA and which TCCA have precisely copied, remain. They are the minimum. In some few cases the totality of a 24 month recert requires some of each. Those on Progressive Maintenance Programs will usually have all the bases covered. Additional Note - progressive maintenance programs seldom coordinate multiple systems and auxiliary aspects of air data testing. Examples are stby altimeter, alternate static, speed sensors, drains.