We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as loose rivets on frames C18 BIS and C19, which could result in a reduced structural integrity of the tail area. We are issuing this AD to require actions to correct the unsafe condition on these products.