Complex sentence: As well as an operational aircraft carrier, "Melbourne" was Flagship of the RAN, a role she received almost immediately following her 1956 arrival in Australia, and fulfilled until her decommissioning in 1982.
Split into simpler sentences: As well as an operational aircraft carrier, "Melbourne" was Flagship of the RAN. She received this role almost immediately following her 1956 arrival in Australia, and fulfilled it until she was decommissioned in 1982.