Airplanes have been in use for almost 100 years, but still remain limited in a very important way: navigation for many airliners hasn’t changed in the past 60 years, despite numerous advances in technology.
Modern airplanes navigate by using a combination of VORs and NDB. VOR stands for Very High Frequency Omnidirectional Range, and is one of the most commonly used navigational aid for modern commercial pilots. NDB stands for Non-Directional Beacon, and is commonly used as a secondary navigational tool for pilots.
A VOR beacon is an older technology, originally created during World War 2. Each radio beacon transmits a unique signal, on a series of 360 ‘spokes’. Each spoke represents a different direction radiating out from the beacon, with the 0 degree spoke facing north, the 180 degree spoke facing south, etc. Modern aircraft use these VOR beacons as waypoints when flying. Many aircraft have to fly directly from VOR beacon to vor beacon, following a precise aerial path. Landing and takeoff patterns are usually based around these and other navigational beacons, requiring extensive interpretation and expertise on behalf of pilots.
GPS navigational tools have become more common in ground vehicles and recreational aircraft, but can’t be used for many airliners. GPS technology is owned by the United States military, and didn’t provide an accurate signal for civilians for many years. In 2000, George Bush signed a new order allowing civilians and the general public to receive high accuracy GPS signals that were previously scrambled.
As GPS navigational tools became more common, the FAA and other flight agencies began looking into incorporating GPS into commercial airliners. Modern commercial aviation requires navigational redundancy: it’s important to have a series of backups in case a primary navigation system fails. GPS signals can degrade in severe weather, and don’t provide the accuracy needed for aircraft landings and takeoffs.
Over the past few decades, several countries have developed competing satellite navigation systems. Galileo is a highly accurate system, developed by a consortium of European nations. It’s expected to provide global coverage by 2019, and will provide 1 meter accuracy anywhere on the globe. China, Russia, and India are also developing competing systems, all in various stages of completion.
Many airliners are developing multi-system satellite receivers, which will allow for highly accurate satellite navigation. Many flight are 20-30 minutes longer than they have to be, due to regulations requiring they follow established navigation beacons. Future GPS technology will allow for direct flights, fuel savings, and faster trips.