With approved SBAS avionics installed; a pilot may plan to use any instrument approach authorized for use with SBAS avionics that meets ICAO aviation requirements as an alternative. The LNAV minima line must be used for planning purposes in case vertical guidance is not available. SBAS removes the Receiver Autonomous Integrity Monitor (RAIM) and fault detection andexclusion (FDE) prediction scenarios.
RAIM is a form of integrity monitoring performed within the avionics themselves. It ensures available GNSS satellite signals meet the integrity requirements for a given phase of flight. By comparing the pseudo range measurements of a number of GNSS satellites, the RAIM function can identify a GNSS satellite failure and issue an alert to the pilot. A minimum of five GNSS satellites is required to detect a bad satellite; at least six GNSS satellites are required to detect and exclude a bad satellite from the navigation solution if the SBAS Avionics receiver has an FDE RAIM algorithm. RAIM checks are a requirement for use of non SBAS avionics.