Careful consideration should be given as how these tasks are managed.   Details of current modifications and repairs require substantiating data supporting compliance with the airworthiness requirements. This can be in the form of a Supplemental Type Certificate, Service Bulletin, Structural Repair Manual or similar approved document. If the airworthiness data for modification and repair is produced by the maintenance organization in accordance with existing national regulations, all detailed documentation necessary to define the change and its approval are to be retained. Scheduled maintenance requirements following STC incorporation are required to be clearly identified as well. We can control and monitor the implementation of ADs, mandatory SBs, and optional SBs (if needed) and circulate advisory related to manufacturer's new instructions regarding avionics, systems, structures, interior, power plant and component maintenance. For any modification based on STC (Supplemental Type Certificate) all supplemental manuals related to this STC should be provided and the STC should be submitted to Civil Aviation for approval