Back to basics navigation

Navigation in the air is the process of maneuvering an aircraft from the origin to a destination while monitoring the process during the flight. The three methods of navigation by air are pilotage (navigating by correlating to visible landmarks from a map), dead reckoning (making calculations of direction and distance or time from a known position), and finally radio navigation (VOR—very high frequency omni-directional radio-range, or GPS—global positioning system). This is why pilots should be proficient in two types of navigation: the use of dead reckoning while using the E6B flight computer and electronic navigation using VOR navigation.

Dead-reckoning navigation usually comes in the form of a navigation log in which the pilot enters information like checkpoints, course, wind direction and speed from winds aloft tables, true airspeed from the pilot’s operating handbook or airplane flight manual, and calculations of true course, true heading, magnetic heading, and ground speed. In addition, the pilot makes calculations of estimated time enroute and arrival at checkpoints and fuel consumption.

Navigation results are developed using a flight computer, which is specifically designed to help with aviation-themed calculations. Flight computers have traditionally been analog but more modern versions use an electronic calculator type interface or an application on a smartphone. The E6B flight computer is a circular analog slide ruler used in aviation. The designation comes from the assigned U.S. Army Air Corps part number in the late 1930s. It usually is made from polished aluminum or card stock paper. One side of the device is used for wind calculations to find the wind correction angle and the other side is used for aviation math calculations for time, distance, and speed.

The use of these analog computers simplifies navigation by dead reckoning and allows the pilot to not depend on navigation from external electronic sources.

The second method of navigation to practice is the use of VOR stations. VOR stations transmit a signal that allows navigation to and from the station on a set azimuth or radial. So instead of following a direct path from your origin airport to your destination airport, the pilot must select a slightly less efficient route that follows a course that goes from VOR station to VOR station.

VORs were first brought online in the early 1950s and were the primary means of navigation until around 2000. The VOR ground station transmits two different signals: the reference phase signal, which is omnidirectional, and the variable phase signal, which rotates at a rate of 1,800 rpm and its phase varies around the station. The receiver in the aircraft gets the signal that has a phase difference, which varies depending on the bearing of the aircraft from the station. Thus, the VOR receiver can show the magnetic bearing of the aircraft from the station.

In 2000, there were about 3,000 VOR stations, but currently approximately 721 stations are left. The FAA has published a plan called VOR Minimum Operational Network (VOR MON). VOR MON is a plan to transition the VOR infrastructure from primary navigation to a backup navigation system during potential GPS outages. 

VOR MON is going to be implemented to enable pilots to navigate via VORs during a hypothetical GPS outage using station to station navigation during the enroute phase of flight and to be able to navigate to an airport with ground-based instrument approaches such as an instrument landing system (ILS), localizer (LOC), or VOR approach. These approaches would be conducted without the use of GPS, distance measuring equipment (DME), or automatic direction finder (ADF) equipment. The VORs that are left should be within 100 nautical miles of at least one airport with these approaches. The final number of VORs after the completion of VOR MON in 2030 will be 590.

However, to be able to utilize VORs and dead reckoning in a situation where GPS is not available, pilots need to be taught the techniques during flight instruction and continue to practice them after obtaining certification. FT