CFR 14-65.31-2014
航空航天. 第65部分:认证,飞行员除了飞行机组人员. 第B子部分:空中交通控制塔运营商. 第65.31节:需要的证书和评级资格.
Aeronautics and space. Part65:Certification: airmen other than flight crewmembers. SubpartB:Air traffic control tower operators. Section65.31:Required certificates, and rating or qualification.