Prototype Stop Bar System Evaluation at Seattle Tacoma International Airport

An interim United States stop bar specification was developed by the Federal Aviation Administration Technical Center. Using the guidance material contained in the interim specification. A full scale prototype stop bar system was installed to protect runway 16R/34L at the Seattle-Tacoma International Airport (SEA). The
system consists of two stop bars which incorporate both inset and elevated red light fixtures. Associated with each stop bar are green inset lead-on lights and microwave detectors that provide for automatic switching of the stop bar/lead-on
light segments. Once installed the SEA stop bar system was operated during air traffic controller training sessions and under actual low-visibility weather conditions for evaluation and user organization familiarization. Air traffic controller and air-carrier pilot questionnaires were distributed and returned to the FAA Technical Center for analysis after completion. The questionnaires were designed to solicit information regarding the effectiveness and reliability of the
stop bar system. As a result of the evaluation, the U.S. stop bar lighting configuration, as developed and described in the interim specification, was found to be satisfactory and acceptable to user pilots.