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Questions about aircraft navigation systems using radios such as VOR and NDB

6
votes
2answers
275 views

What are these FAA facilities in Seattle doing?

While walking in Discovery Park I discovered this radar dome with FAA notices on its fence. And not far away I cam across this small FAA signed radio antenna and shack. Any idea what these ...
15
votes
3answers
1k views

Are NDBs and VORs dying as a navigational method?

I am new to aviation, so bear with me on this question: I have read in multiple places that the VOR/NDB navigational aids are dying out to GPS. Is this true? Are more modern aircraft being built with ...
0
votes
0answers
6 views

UHF transmitter Range for 50Watts [migrated]

Very curious to know the range of 50Wats transmitter of UHF range in nautical miles?The antenna used is 1/4 wave antenna of Jaybeam company. Can someone tell the exact formulation to find out the ...
0
votes
1answer
98 views

How do I calculate the aircraft's deviation from track in this exam question?

I’ll have my PPL exam soon. I asked my instructor at the school about this question and even he doesn’t know the answer. I’ll appreciate your help. Question 22 Flight from point A to point ...
0
votes
1answer
122 views

Does an aircraft equipment suffix denote how many VOR radios are installed?

I'm studying IFR. Does an aircraft equipment suffix specify if and how many VOR radios are installed? I'm guessing that the suffix is used by ATC to know if they can give you an RNAV or a an approach ...
1
vote
1answer
114 views

How the Log Periodic Dipole Antenna of Localiser help in varying modulation depth?

Here Albert Helfrick speaks about 40% modulation depth for each tone in a localiser radio signal. However latest manuals of ILS manufacturers and google source speaks about 20% modulation depth, not ...
3
votes
3answers
302 views

Why are the modulation depths of the localiser and glideslope different?

Why do we use a modulation depth of 20% (for 90Hz and 150Hz each) in the case of the localiser and 40% (for 90Hz and 150Hz each) in the case of the glideslope? Why not use 20% for both?
2
votes
1answer
257 views

Why does the glideslope use UHF when the localiser uses VHF band?

Why does the glideslope use UHF, while the localiser uses the VHF band? I mean, the glideslope could have used the VHF band too, or vice versa, so why is it so?
3
votes
2answers
297 views

Why do localizer/glideslopes use 90/150Hz specifically?

Why is it that localizer and glideslope system are using 90 Hz and 150 Hz frequencies only, instead of some other LF such as 75 Hz? Part two of my question: How does the modulation depth differ for ...
7
votes
1answer
293 views

What error is left uncorrected when “fast IRS align” is done?

As far as I understand, there are two ways to align the IRSs in B737s: "Full align" and "fast align." For a full alignment, you rotate the IRS selector from OFF to NAV, and for a fast alignment, you ...
5
votes
2answers
708 views

Why doesn't civil navigation equipment support TACAN?

Now even handheld aviation radios have GPS, VOR and ILS! I wonder why modern LCD screens with radios and navigation doesn't have TACAN? Is it coded, not useful, not certified or not used anymore? I ...
2
votes
0answers
120 views

How does one reverse direction on a VOR radial?

Tracking inbound, say on R-270, how do I track outbound on the same R-270? What intercept heading shall I fly?
3
votes
0answers
147 views

Does EASA approve the use of localizer back course?

Does EASA approve the use of localizer back course? Are there some countries in Europe that allow it?
-4
votes
1answer
278 views

What are the differences between VORTAC's and NDB's?

What are the differences between VORTAC's and NDB's?
10
votes
3answers
2k views

Is it possible for a civilian to use a VORTAC station?

Suppose you have a Cessna 208 Grand Caravan Amphibian and you want to use VORTAC stations on military bases (or somewhere else). Is it possible? Is it legal?
0
votes
0answers
352 views

What are the differences between VOR/DME and VORTAC? [duplicate]

Yes, long answers are needed but what are the differences ?
2
votes
0answers
38 views

Where can I find the specific power output of a specific NDB?

As a rule of thumb I can get an approximate range of an NDB with the formulae: Over sea: range=3SQRT Power Over land: range=2SQRT Power To use this formula I need to find out what Power has the NDB ...
3
votes
1answer
279 views

What is the best pair selection algorithm?

Distance Measuring Equipment selection criteria is said “those closest to the aircraft and which intersect at an angle between 30 degrees and 150 degrees" (also said one whose geometry is closest to ...
6
votes
1answer
463 views

How can I triangulate a position using two DMEs?

What is the formula for determining an aircraft's position (latitude, longitude) using barometric altitude and the ranges to two DMEs?
4
votes
1answer
354 views

What are the differences between each ILS category?

I want to know the characteristics of the different categories of Instrument Landing System (ILS): CAT I, CAT II, CAT IIIa, CAT IIIb and CAT IIIc. What are the differences between them? (This ...
0
votes
1answer
170 views

Do UAVs use ground-based navaids?

When I Googled it seems it is not common to use Vortac like systems from UAVs as a backup to GNSS outages, like in manned aircraft. And also I haven't seen any equipment designed for just UAV ...
3
votes
1answer
528 views

What do “LC/P” and “PTD” stand for in reference to airport communications?

When I pull up the Colorado Springs (KCOS) Airport Comm frequencies in Skyvector or in FAA database there are some frequency listed as "LC/P" and "PTD". Would someone explain what those acronyms stand ...
4
votes
1answer
270 views

Is Ground Direction Finding commonly used?

I've recently come across the concept of Ground Direction Finding. My (limited) understanding of it is that it is a system that allows you to see where a VHF transmission is coming from. I gather it ...
13
votes
1answer
4k views

What is the night effect?

I read the night effect takes place in radio navigation, especially VOR and NDB. My questions are: What is its nature? Why does it occur? What are the consequences of it?
8
votes
2answers
2k views

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

I saw in book that the cone of confusion of VOR is 40 degrees, and NDB is 50 degrees of each side! Isn't it too much? Maybe it's a mistake, or old information(book printed in 2004) Clarify please: ...
3
votes
1answer
757 views

Why do we have to manually tune VOR receivers?

As the VOR frequency is automatically selected when the DME is selected, under what system conditions is manual tuning of the VOR required? (aviation-safety-bureau.com)
5
votes
1answer
466 views

What are outer marker horizontal dimensions at 3 degrees ILS path?

What is the outer marker "distance" along the flight path of a 3 degree ILS? I provide my two approaches below, but as they contradict each other, I am asking this question to learn the proper answer....
4
votes
1answer
573 views

What are en-route VHF marker beacons (75 MHz)?

ICAO Annex 10, Volume 1 contains a section that gives the specification for en-route VHF marker beacons. What are they? I suspect they are a relic of the past. Are they still in use anywhere in the ...
16
votes
2answers
13k views

How does TACAN work?

How does the Tactical Air Navigation (TACAN) system work? How is it different from the VHF Omnidirectional Range (VOR) system? Please explain in the simplest possible way.