The introduction of technology has continually contributed to improvements in the way we navigate in the National Airspace System (NAS). In the 1940s, the NAS operated primarily on fixed routes and procedures supported by legacy ground-based navigation aids. In the early 1990s, additional capability was added when the FAA approved Global Positioning System (GPS) equipment for use. These navigation systems have performed well over the years, safely guiding countless aircraft through the NAS. With the continuous growth in air travel, however, navigation technology must continue to evolve to meet growing demands, address delays, and prevent future gridlock.
To meet this challenge, the FAA is transitioning the NAS to Performance Based Navigation (PBN). PBN includes both Area Navigation (RNAV) and Required Navigation Performance (RNP). RNAV and RNP operations are enabled primarily by satellite navigation in the form of the Global Navigation Satellite System (GNSS). GNSS includes GPS, Wide Area Augmentation System (WAAS), Aircraft Based Augmentation System (ABAS), and other satellite navigation systems developed to support aviation. Using GNSS, RNAV and RNP routes and procedures can be flown virtually anywhere in the NAS, in all phases of flight.
GNSS provides an excellent and valuable service, but is susceptible to interference (intentional and unintentional) so to mitigate GNSS vulnerabilities, the FAA is developing a robust and resilient navigation infrastructure. This layered backup navigation capability includes the use of Distance Measuring Equipment (DME) and Very High Frequency Omni-directional Range (VOR) to provide a basic conventional capability in the event of GNSS outages.
The FAA is also transitioning in the use of Light Emitting Diode (LED) technology for visual navigation aids or more commonly-referred to as lighting systems. LEDs provide a range of benefits to both pilots and to the FAA in terms of providing more cost-effective service to the users of the NAS.