What type of supplemental navigation equipment is necessary with a WAAS-capable GPS navigator for an RNAV instrument approach?

For an RNAV instrument approach using a WAAS-capable GPS navigator, no additional navigation equipment is required. The WAAS (Wide Area Augmentation System) enhances the integrity and accuracy of GPS signals, making it suitable for precision instrument approaches.

When the WAAS functionality is integrated into the GPS system, it provides the necessary vertical and lateral guidance essential for RNAV approaches. This means that a single WAAS-equipped GPS unit is capable of complying with the requirements for approach procedures without needing supplementary systems like a secondary GPS, ADF, or VOR receiver. WAAS-equipped GPS ensures a level of performance that meets FAA standards for these types of approaches, allowing pilots to execute landings with confidence and precision based solely on the information provided by the WAAS-enabled GPS system.