This document has been declared "Stabilized" and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability or technical requirements. New technology may exist. The scope of this document is limited to descriptions of the display characteristics of the Flight Dynamics, Inc. (FDI) Model 1000WS Head up Guidance System (HGS) as installed on the Boeing 727 airplane and certified by the Federal Aviation Administration for use in Category III landing operations. The symbology depicted in this document is referenced to the particular pilot task(s) for which it was designed. Also included are descriptions of operational features of the particular symbol along with any associated criteria regarding symbology constraints, source data, or position error.