# How a VOR Works - By sending out 2 signals with a constant frequency, known as a *reference phase* and a *variable phase* a VOR receiver is able to interpret its direction from a station be comparing the difference between the reference and variable phases - Some VORs are equipped with [[Distance Measuring Equipment (DME)]] that can be used to determine an aircrafts distance from the station (assuming the aircraft is equipped with DME) # Calculating the Current Radial - VOR receivers compare the reference and variable signals and compare them to determine the current radial of the aircraft - [Desmos Graph of VOR Signals](https://www.desmos.com/calculator/cr7revsiuf) ## 360 Radial - The graph below displays the *reference phase* as a red line, and the *variable phase* as a blue dashed line <iframe src="https://www.desmos.com/calculator/cr7revsiuf" width="100%" style="min-height:500px"></iframe> - Because they are aligned, the receiver interprets this as being on the $360 \degree$ radial ## 180 Radial <iframe src="https://www.desmos.com/calculator/fex6tinnbr" width="100%" style="min-height:500px"></iframe> - Above is an example of what the VOR receiver would get if it were positioned on the $180 \degree$ radial # Calculating Time to the Station $ \frac{time \space in \space seconds}{degrees \space of \space bearing \space change} = minutes \space to \space station $ > [!question]- if 2 minutes is required to fly a bearing change of 10 degrees, the aircraft is how many minutes away from the station? > 2 minutes $=2 \times 60 = 120$ seconds > $\frac{120}{10} = 12$ minutes to the station # Calculating Miles Off Course - The 60:1 rule states that *if you're off course by 1NM after 60 miles, you have a 1 degree tracking error* <div class='iframe-container'><iframe width="560" height="315" src="https://www.youtube.com/embed/WiXU2OrDeNo?si=4jlWA0OnPYV3nkTW" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe></div> # VOR Service Volumes - While the FAA transitions to the minimum operational network (MON) legacy service volumes are still used to supplement the new service volumes - more information about the MON can be found here: [FAA MON Information](https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gbng/vormon) ![[20-02-NavAid-Service-Volumes-DVT-2020.pdf#page=6]] # Identifying VORs ![[Pasted image 20240204113712.png]] - In the image above, we can see that the VOR frequency is 112.1 - The VOR can be identified by listening to the morse code identifier - Additionally, the VOR service volume falls under VH, and H refers to the Tacan service volume # ![[VOR Inspection]] # Loading VORs in ForeFlight ## Loading VOR as Fix ![[Loading VOR in foreflight.png]] - to load a VOR / VORTAC into foreflight, you can simply type in the identifier - note that if the VOR is located on the airport, make sure to load the VOR identifier instead of the airport - in the picture shown above, "ORL" should be loaded instead of "KORL" ## Loading a VOR Radial and Distance ![[Loading radial and distance in foreflight.png]] - to load a radial and a distance, simply type the VOR/radial/distance in nm - this will load a fix that is located at the radial and the distance from the fix ## Loading Cross Radials ![[Loading cross radials in foreflight.png]] - to load a cross radial, simply type VOR|RADIAL/VOR|RADIAL - the example above shows the intersection of the 270 radial from the ORL vortac and the 180 radial from the OCF vortac