The traffic separation scheme (TSS) in the approach to Boston, MA, consists of three parts: Two precautionary areas and a TSS. The specific areas in the TSS in the approach to Boston, MA, are described in §§ 167.76 and 167.77. The geographic coordinates in §§ 167.76 and 167.77 are defined using North American Datum 1983 (NAD 83), which is equivalent to WGS 1984 datum.