The WAAS (Wide Area Augmentation System) enhancement to the GPS system will be shut down for two hours and then restarted this Friday, sometime between 1600 and 2200Z. WAAS improves the accuracy and integrity of the GPS signal and will provide ILS-like instrument approaches into almost every airport. Friday's shut-down is part of the continuing progress toward certifying WAAS for actual IFR operations. Some newer handheld VFR GPS receivers are already using the WAAS signal to improve accuracy, but the temporary loss of the WAAS signal will not significantly affect those users.
This test brings WAAS closer to its scheduled December 2003 implementation date. WAAS enables pilots with certified receivers to access airports and runways using new instrument approaches that have vertical guidance. This first stage of WAAS enables pilots to fly approaches to minima approaching that of an ILS when appropriate airport infrastructure is present (e.g., approach light systems and runway pavement markings). "While this isn't the ILS replacement as originally hoped for, this is an excellent first step. It will enable general aviation pilots to access approaches that provide improved quality and vertical guidance at many general aviation airports that don't have ILS systems today," explained Randy Kenagy, director of advanced technology for AOPA.
Because avionics are expected to emerge before WAAS is certified, pilots should be able to immediately utilize the benefits of WAAS. AOPA is pushing the FAA to establish approaches at airports most used by AOPA members before WAAS is implemented to make it useful right away. AOPA is also seeking operational approvals including the ability to operate using WAAS under IFR without any other navigation equipment required on board the aircraft.