27 votes
Accepted

How does the ADF null positions find where the NDB is?

Short answer Do you find the null position, then assume it's 90 degrees from the beacon? That's correct. For the antenna pattern shown in the question, the angle between direction of nulls and peaks ...
mins's user avatar
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15 votes

What are the differences between a VOR and a VORTAC?

VOR stands for VHF Omnidirectional Range. It is a navigation beacon intended for civil use and provides a user with a radial to/from the station. It works on frequencies between 108.00 and 117.95 MHz....
DeltaLima's user avatar
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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 ...
Cipriano Kritzinger's user avatar
11 votes
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What's the meaning of underlined frequency in sectional chart nav aid box?

Navigation receivers can be used as a fall back for regular VHF/HF radio transceivers Before data links, there were essentially two types of radio receivers in the flight deck, and this is still the ...
mins's user avatar
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11 votes

Why would an ILS installation need a “reflecting surface” around the glideslope antenna?

You wrote that intuitively, one would expect that UHF-radio-wave-reflecting surfaces near your glideslope antenna would be a bad thing, due to the potential for multipath interference However, ...
Rainer P.'s user avatar
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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 ...
mins's user avatar
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9 votes
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Why do IFR charts show TACAN paired frequencies when there is no collocated VOR?

Your supposition is correct. Tuning the paired frequency will allow you to receive DME information from the TACAN. If your DME tuning is through your VOR/ILS receiver, the VOR output will be flagged ...
Gerry's user avatar
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8 votes

How do you know if a VOR is High, Low, or Terminal?

The range of the VOR is included in the Airport/Facility Directory data under the name class From A/FD legend: Example: Service volume for each class:
mins's user avatar
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8 votes
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Where does the Garmin G1000 Nav ID come from?

Garmin doesn't explicitly state the method in the documentation I can find, but I believe the answer is #1. It decodes the Morse code and displays that value. I say that for two reasons: First; ...
Gerry's user avatar
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8 votes
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What, effectively, does a navaid being unmonitored mean?

Actually it doesn't have anything to do with voice capabilities: 5-3-5. UNMONITORED NAVAIDs a. All VOR, VORTAC, and ILS equipment in the NAS have automatic monitoring and shutdown features in the ...
Ron Beyer's user avatar
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8 votes

What is the difference between unserviceable, unusable, and not maintained?

UNSERVICEABLE (abbreviated U/S) is the ICAO version of what the FAA used to call OUT OF SERVICE (abbreviated OTS). To my mind this is less clear and a step backwards, but at least it's in line with ...
randomhead's user avatar
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7 votes
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What official government document should a pilot check to determine what magnetic north a VOR was set to when it was commissioned?

The chart supplement does list the magnetic variation of the VORs. Looking under the "radio aids to navigation" section for a nearby airport, it's listed at the end of the line, right after the ...
fooot's user avatar
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7 votes
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What is magnetic variation under RADIO AIDS TO NAVIGATION in FAA Chart Supplement, and How to use it?

Conceptually, VORs (and VORTACs) emit radials which are fixed lines radiating out from the VOR. One of those radials is designated "north" (0º, 360º) and all of the other radials are ...
randomhead's user avatar
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7 votes
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Navaid information on SID

Those are the low- and high-altitude enroute charts where you find Boston VOR. There is a PDF document called Legends & General Information that is found on the bottom of the terminal procedures ...
wbeard52's user avatar
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6 votes
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Is it true that there are VOR/DME and/or TACAN stations in the oceans?

There are no ship-based VOR's or TACAN's specifically dedicated to transatlantic flights. Transatlantic flights navigate using the inertial navigation system and GPS. TACAN's are used on board naval ...
DeltaLima's user avatar
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6 votes

What kind of input is used by NASA's TASAR?

The answer is "All of the above." The left hand side of this slide from a NASA Powerpoint deck pretty much covers your question. The full slide deck from the presentation can be seen here.
Juan Jimenez's user avatar
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6 votes

Is flying direct to a navaid considered a leg with track guidance?

I see that if a specific course is not required, the aircraft will turn direct to the navaid on any course which is suitable with its performance. But the aircraft always have track guidance regarding ...
Michael Hall's user avatar
  • 26.1k
5 votes

What is the minimum separation for navaids to work properly without interfering?

VOR/DME and NDBs can't interfere with each other: they work on completely different wavelengths, so you could have a VOR right next to an NDB and they'll work just fine. Similarly, VORs on different ...
GdD's user avatar
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5 votes
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Why are the VHF and UHF airbands directly adjacent to frequency bands used by vital radionavigation aids?

The most obvious reason is that the ITU allocated the VHF and UHF bands for aviation purposes generally, and then aviation authorities had to split those limited bands into adjacent comm and nav sub-...
StephenS's user avatar
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5 votes

How do you know if a VOR is High, Low, or Terminal?

Typically terminal VOR's do not have compass roses around them if they are strictly terminal VOR's. I can't find an example of one so I don't have an image for it. Edit I found an example: Source: ...
Ron Beyer's user avatar
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5 votes
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Why do none of the procedures for EFSA use the SVL VOR-DME?

According to the Finnish AIP, LINNA (SVL) is only a DME, not a VOR/DME.
tml's user avatar
  • 756
5 votes
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Why do navaids noted in the chart supplement have a W next to them?

“Most VORs are equipped for voice transmission on the VOR frequency. VORs without voice capability are indicated by the letter “W” (without voice) included in the class designator (VORW).” I assume ...
JScarry's user avatar
  • 7,464
4 votes

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

Another good one for airports and navaids: http://opennav.com/ - has VORs, waypoints, etc.
TheStoryCoder's user avatar
4 votes
Accepted

What's exact offset degree dividing localizer and LDA?

The maximum angular offset for a LOC is 3° for FAA and 5° for ICAO. Everything else is named either LDA (FAA) or IGS (ICAO). In ICAO wording, any ILS which doesn't meet all ILS requirements is an ...
mins's user avatar
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4 votes

What are the units for the bearing to center of an airport from radio aids to navigation in chart supplement?

It's almost certainly magnetic. Page 12 of the Chart Supplement (sample airport information) has this information at the bottom (emphasis mine): All bearings and radials are magnetic unless otherwise ...
Pondlife's user avatar
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4 votes
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What are the modulation parameters of a DME?

DME principle Source. The interrogator sends a pair of pulses, the DME transponder sends back identical pulses after a fixed delay of 50 μs for X channels, 56 μs for Y channels. The interrogator is ...
mins's user avatar
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3 votes
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What is the difference between an Non-Directional Beacon and a Compass Locator Beacon?

Normally "Compass Locator Beacons" were co-located with the outer marker for ILS approaches. A "compass locator beacon" is an NDB beacon specifically to drive the radio compass. A radio compass was a ...
Ron Beyer's user avatar
  • 36.2k
3 votes

Reason for the multiple sidelobes in an ILS glideslope signal

All directional antennas have sidelobes (and all real antennas are at least somewhat directional). I won't get into detail of the fundamental physics reasons behind that, as that's beyond the scope of ...
pericynthion's user avatar
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