What must you check during preflight if you plan to use GNSS procedures?

When planning to use Global Navigation Satellite System (GNSS) procedures, checking GPS NOTAMs (Notices to Airmen) is essential. This is because NOTAMs provide critical information regarding the operational status of GNSS systems, including any outages or anomalies that may affect performance. The performance of GNSS navigation can be influenced by various factors such as satellite availability, system reliability, and any potential interference that could compromise navigation accuracy.

Knowing the current state of the GNSS service helps ensure that the navigational information you rely on is accurate and that you are prepared for any potential issues that could arise during your flight. By staying informed through GPS NOTAMs, you can enhance situational awareness and make informed decisions about your flight operations, ultimately ensuring the safety and effectiveness of your navigation procedures.

While other aspects such as weather, fuel consumption, and aircraft maintenance records are important considerations for overall flight safety, they do not specifically pertain to the requirements for using GNSS procedures. Therefore, while all these factors have to be checked during preflight, the most relevant to GNSS procedures are the GPS NOTAMs.