How can a pilot check the status of RAIM before a flight?

The most effective way for a pilot to check the status of Receiver Autonomous Integrity Monitoring (RAIM) before a flight is by using a Multi-Function Display (MFD) and reviewing a NOTAM. The MFD often provides tools and information that allow the pilot to evaluate the GPS system's integrity and availability for the intended route. Additionally, NOTAMs can provide crucial updates on the status of navigational aids and any outages or maintenance work that might affect GPS signal reliability.

Checking the MFD allows pilots to obtain real-time data on their aircraft's navigation systems, including RAIM predictions, which are essential for ensuring that the GPS will function correctly throughout the flight. The NOTAMs further enhance this assessment by informing pilots of any temporary conditions that might affect navigation.

Other methods such as consulting flight plans, examining weather reports, or reviewing prior flight logs do not directly provide the necessary real-time integrity status of the GPS system. Flight plans may not include specific integrity data, weather reports focus on meteorological conditions rather than navigation integrity, and prior flight logs are retrospective and cannot assure current RAIM status. Therefore, leveraging MFDs and NOTAMs offers a more reliable and accurate means of checking RAIM status prior to flight.