A person employed as an officer or member of the flight crew of an aircraft, who would
            otherwise have dual coverage under the social security taxation and coverage laws
            of both the United States and Belgium, will only have coverage in the country where
            the employer is headquartered. This rule is applicable whether the person is in the
            other country on a temporary or permanent basis. Non-travelling personnel (e.g., ground
            crews or administrative staffs) will be subject to the laws of the country where they
            work unless they qualify as a detached worker (see RS 02001.267).