What should a pilot check before a GPS approach?

Before executing a GPS approach, it is essential for a pilot to check Receiver Autonomous Integrity Monitoring (RAIM) availability. RAIM is a critical feature of GPS that ensures the reliability and accuracy of the position information being provided. Essentially, it helps the pilot determine whether the GPS signals are providing valid data for navigation, particularly during an approach phase where precision is crucial. If RAIM is not available, it may indicate that the GPS system is not functioning properly, which could lead to unsafe navigation situations, especially in poor visibility or complex airspace environments. Ensuring RAIM availability helps to confirm that the GPS is suitable for the approach, thereby supporting safe landing operations.

While it’s important for pilots to be aware of the weather conditions along their route to ensure safe flying, review altitude restrictions for compliance with airspace regulations, and maintain communication with ground services for logistical support, these factors do not directly impact the readiness of the GPS system for a precision approach as RAIM does.