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27 votes

Why is there a grid below the antennas of an VOR?

I think this is an example of a counterpoise: [It] is a network of suspended horizontal wires or cables (or a metal screen), used as a substitute for an earth (ground) connection in a radio antenna ...
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26 votes
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Why is there a grid below the antennas of an VOR?

I would imagine the main reason is to make the performance of the antenna system more predictable and consistent. Many antennas systems need a ground reference. All antenna systems are affected by ...
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22 votes
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Why am I not getting the "TO" VOR flag as I think I should?

A quick review of the US Chart Supplement shows that the Lovelock VOR (LLC) is unusable at your current altitude and position. The VOR is 3.6 NM North by Northwest from the field. Your aircraft is 24....
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19 votes
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What radial is the aircraft crossing?

A radial is always pointing (radiating) away from the VOR. But your instrument shows the TO/FROM indicator as TO. So you are crossing a 210 course towards the VOR, which means you are on the 030 ...
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18 votes
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What causes the phase to change in a VOR?

The latest decades VOR are Doppler VOR (DVOR) where the bearing signal is produced by a 14 m diameter circular array of fixed Alford loops antennas. An additional central antenna radiates the ...
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17 votes
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What is the difference between conventional VOR and Doppler VOR?

Short answer: There are several types of conventional VORs using either rotating or static antennas. What they have in common is: They are relatively compact. Bearing is determined from a HF signal ...
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17 votes
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Do some modern VORs not spin?

There are no spinning parts in the VOR. It typically uses 60 antennae in a phased antenna array to steer the beam in a rotating sweep. The VOR transmits a constant omnidirectional signal. The phase ...
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17 votes
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Is VOR identification automated in modern avionics?

Modern air transport and bizjet avionics do decode the audio ID and provide it digitally on the data output bus. This data is displayed on the Nav display or RMI (depending on Mode) along with the ...
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14 votes
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Where to find a waypoints/fixed points, navaids and airports database?

Nice question. There are several ways how to get these information. http://www.fallingrain.com/: free to use, no registration needed. World database of the airports and waypoints. From these ...
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14 votes

Can a pilot use their GPS/FMS to fly a VOR or NDB approach?

In the US they can (Effective: May 26, 2016). This change allows for the use of a suitable RNAV system as a means to navigate on the final approach segment of an instrument approach procedure (IAP) ...
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14 votes
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Are NDBs and VORs dying as a navigational method?

Yes, without a shadow of a doubt. Many airports now publish GNSS (Generic term for all types of satellite navigation) approaches, completly negating the need for those aids even during complex, ...
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13 votes
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Can VOR indication be reliable if one of its antennas breaks?

No, it should not be used. Twin antennae, as you have shown, are balanced and fed into a balun (BALanced to UNbalanced) to feed the single transmission line to the receiver. Together, they provide ...
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13 votes
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How are there some Victor airways that exceed the service area of the VORs they are identified by?

It says it right there on the page where the service volumes are described in the AIM: 1-1-8. Navigational Aid (NAVAID) Service Volumes c. Standard Service Volume limitations do not apply to ...
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13 votes
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Why would a VOR be decommissioned leaving the DME?

Many older Air Transport Airplanes have no GPS. I'm a pilot since 1970. I operated A330 for 5 years until 2000 without GPS. The average IRS position (Inertial Reference Systems) in the FMS was updated ...
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12 votes

Why do we have to manually tune VOR receivers?

As pointed out in the comments, I think you have things turned around. If you select the frequency of a VOR that has a co-located DME, the system will automatically also select the DME frequency. Thus,...
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12 votes

How wide is the cone of confusion above a VOR and NDB?

Isn't it too much? No, it isn't. VOR's and NDB's are pretty old technology. VOR's were introduced in the 1930's and 40's, but are still commonly used today. If you have a cone of confusion of 45 ...
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12 votes
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How wide is the cone of confusion above a VOR and NDB?

The value +/-40° is correct, but need to be interpreted. The primary reason of the existence of a "silence" (confusion) cone is a design choice to increase navaid range. Range and "...
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12 votes

Are NDBs and VORs dying as a navigational method?

Yes, it is true. This FAA page has more info. The Very High Frequency Omni-directional Range (VOR) Minimum Operational Network (MON) provides a conventional navigation backup service in the event of ...
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12 votes
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What is Automatic Radial Centering on a VOR indicator?

As the name indicates, this automatically centers the CDI needle, by selecting the appropriate TO radial. From the manufacturer of INS 422, an integrated navigation system including a VOR: Pushing ...
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12 votes

What would be the likely indication on the VOR for the below question?

The aircraft is on a radial. Just not the one marked on the diagram. Notice that figures 1, 3, and 4 all have heading 210° dialed at the top of the instrument. However, figure 2 has heading 120° ...
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11 votes
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How can a pilot fly a distance of 594 NM connecting two VOR's?

You are correct that VOR's rarely have a range of more than 200 NM. However, Alta Floresta VOR (ATF) is colocated with an NDB (and DME). In spite of less accuracy, NDB's have a much greater range (...
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11 votes
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Why wouldn't KJFK offer the ILS for 22L?

JFK ARR ILS 22L/22R DEP 22R If conditions dictate the use of JFK ILS RWY 22L approach, then (1) the JFK Area owns Belmont airspace 3,000' and below, (2) releases Coney airspace to LGA and LIB, (3) ...
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11 votes
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Are there two navaids on the same frequency close enough to be confused?

Short answer ICAO recommendations include a protection for same-frequency navaids, restricting the received power of undesired stations to a level preventing interferences. To meet this restriction ...
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11 votes

Why is the treatment of magnetic variation different for NDB and VOR?

The reason is, that for a VOR, the receiver in the aircraft determines the radial based on calculating the phase shift and as the VOR is oriented to the magnetic north of its location, we need the ...
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10 votes
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Are nearest VOR stations always tuned to?

Your example is a bit confusing because it seems to be a GPS-based route, it may be better to a look at a more 'realistic' one, where you're using only VORs for navigation. The reason to tune a second ...
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9 votes
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Can a pilot use their GPS/FMS to fly a VOR or NDB approach?

No, you still have to monitor the underlying NAVAID. You just have to read further in that same section of the AIM. Reference the most recent edition of the AIM, which has Change 3 dated April 27, ...
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8 votes
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VORTAC symbol over KMOT airport - is the small dot the center?

The dot in the center of the star means that there is a rotating beacon available on the airport from sunset to sunrise. See the FAA Aeronautical Chart Users Guide Page 8. The actual center of the ...
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8 votes

How does the VOR receiver pick up the signal and how are the needles controlled?

Your basic understanding of the underlying electronic principles is correct: The VOR receiver detects a phase offset between two signals, which tells the receiver what radial the aircraft is currently ...
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  • 67.4k
8 votes

Where to find a waypoints/fixed points, navaids and airports database?

I use the National Flight Data Center at http://nfdc.faa.gov I had to write them a letter explaining why I wanted the data (http://fplan.sf.net) and they provided me with a login. Now, every 56 days,...
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