If diverting to a filed alternate due to below minimums, what is true about the use of GPS?

The correct answer is that you may fly a GPS-based approach if there is an operational ground-based NAVAID. This is because regulations allow the use of GPS approaches, provided that the necessary conditions are met, which include the availability and operation of ground-based NAVAIDs that can support the navigation requirements during the approach.

In the context of diverting to a filed alternate due to weather below minimums, the presence of a functioning ground-based NAVAID complements the GPS system, ensuring redundancy and enhancing navigational precision. It aligns with regulatory guidance that permits approaches using advanced navigation technology as long as traditional navigation aids are also operational. This contributes to safety by enabling pilots to utilize both GPS capabilities and the reliability of ground-based systems.

Understanding this aspect reflects the modernization of navigation in aviation, where pilots are increasingly equipped to use GPS while still respecting the established infrastructure provided by ground-based NAVAIDs.