During a WAAS GPS approach, what does LNAV+V indicate?

LNAV+V stands for "Lateral Navigation with Vertical Guidance." During a WAAS (Wide Area Augmentation System) GPS approach, this designation indicates that the approach provides lateral guidance and allows for vertical guidance that is based on the barometric altimeter.

When flying a LNAV+V approach, pilots are expected to utilize the barometric altimeter for vertical navigation during their descent. The approach aids in maintaining the correct vertical profile, especially when transitioning from the initial approach phase to the final approach phase. Unlike precision approaches, which use electronic glide slopes, LNAV+V provides an advisory vertical guidance, making it essential for pilots to be attentive to their barometric altitude settings.

In conclusion, the indication to use the barometric altimeter for descent in a LNAV+V approach ensures that pilots can accurately manage their descents while following the lateral path provided by the GPS, enhancing safety and precision during the approach phase.