ABSTRACT
Certifying new commercial aircraft models is a tremendous responsibility for the certifying authority. The National Aviation Authority (NAA) of the country of origin of that new aircraft model is the authority that needs to fulfil this task. The NAA of the country where the aircraft producer resides is the authority that certifies the airworthiness of the aircraft. A new aircraft type, its engines and all components installed in that aircraft need to obtain an Original Type Certificate for being allowed to fly. When, in due course, the aircraft type is modified – for instance by installing another engine type – an amended type certificate is required. When a design deficiency is discovered in an aircraft or one of its systems, an airworthiness directive note will be issued, ordering a modification or replacement of the deficient part within a specified time frame.
