Each aircraft governed by EASA or UK CAA regulations is issued with a Certificate of Airworthiness. While this non-expiring document forms the foundation of aircraft compliance, annual validation through specialised Airworthiness Review Certificate (ARC) services is essential. The ARC is issued by the National Aviation Authority (NAA) upon the recommendation of an approved Continuing Airworthiness Management Organisation (CAMO) and holds validity for one year. Additionally, these crucial ARC services may be extended twice for a one-year period before mandatory renewal. It is imperative to note that an aircraft may not legally take flight with an invalid ARC.