Rules of the Air Article 66
Small aircraft（excluding helicopters）operating as passenger or cargo flights shall follow IFR rules and flying via ATS routes in area where ATS routes have been established.
中文原文 飛航規則第66條
小型航空器在有航路地區作客、貨運作時，應按儀器飛航規定在航路上飛航。
但直昇機之飛航，不在此限。
但直昇機之飛航，不在此限。