The GPS1BHAL is a hybrid digital cockpit upgrade from General Electric (GE) for Boeing 727-200s, 737-200s, and 737-300s. It includes replacement of the existing instrumentation, installation of a new fully integrated GPS Navigation and Autopilot System, and a Flight Management System (FMS) with redundant navigation sensors for improved reliability. Additionally, the GPS1BHAL provides Category II/III Reduced Vertical Separation Minima (RVSM) capability and an Electronic Flight Instrument System (EFIS). The system also provides integration with existing navigation and communication equipment and provides basic terrain awareness, windshear warning, and pre-arrival alerts. The GPS1BHAL is a custom solution from GE that provides improved reliability, redundancy, and navigational performance over legacy avionics equipment.