31

Short two-bullet answer (1) Differences between VOR/DME and TACAN include: TACAN uses UHF (VOR uses VHF) to increase bearing determination accuracy; a single frequency for range and bearing (VOR/DME uses two frequencies); two small rotating drums with parasitic antenna elements (VOR uses a large circular array of antennas). A VOR/DME station actually uses ...


20

Electromagnetic waves propagate actually using different means at the same time: Space wave (direct line of sight) Ground wave (or surface wave) Sky wave. Note: Electromagnetic waves are not entirely understood. The terminology around ground waves varies with authors. Some authors don't make a difference between space and ground wave, they just ...


16

Totally legal to tune it up & use it. If it is a VORTAC, it will work just like every other VORTAC out there. If it is a TACAN, you may be able to get DME from it, but you won”t get bearing from it without a TACAN receiver. Many, perhaps most VOR’s out there are in fact VORTAC’s — the TACAN station is colocated with the VOR. It is possible to have a VOR-...


14

We can find the exact method to use online, after all this is a common 3D trigonometry problem. I'll use Michael Geyer US DoT report: Earth-Referenced Aircraft Navigation and Surveillance Analysis. The principle is: The two DME distances determine two spheres which intersection is a circle. The aircraft is on this circle. The aircraft altitude determines a ...


14

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, critical phases such as approach and landing and take off and departure. Modern GNSS systems are capable of utilising synthetic VORs where even when doing something ...


12

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, I'm guessing that what you perhaps meant to ask is under what conditions do you manually tune the DME frequency. If that is NOT what you are asking, put a ...


12

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 a loss of Global Positioning System (GPS) signal. The MON includes the minimum number of geographically situated VORs in the contiguous United States (...


10

Civilian aircraft can use part of TACAN, the Distance Measuring Equipment (DME) signal is the same as civilian DME. As for the directional component one big reason is that the military don't want you to. Even if the military didn't mind there would likely be no demand as the costs of using TACANs outweigh the benefits. TACAN is essentially a more accurate ...


7

Your question presumes that a "fast align" can be performed instead of a "full align", but is in some way deficient. But this is not the actual usage. Starting from cold (unpowered), the IRS must always go through a full alignment to find true north, a process which takes about 7 minutes. The IRS is also manually given an initial position, usually via the ...


7

Absolutely. A VORTAC is nothing more than a VOR colocated with a TACAN. Most VOR-DMEs in the US are VORTACs. If there happens to be one located on a base you are certainly still able to use it.


7

Yes, "D" is correct. A picture is worth a thousand words......


6

The category specs are easily found on Wikipedia. Here is a concise view of the ILS approach minimums, as far as the crew is concerned. Cat I DH: 200 ft (61 m) or more RVR: 1,800 ft (550 m); at some airports 1,210 ft (370 m) is approved. For single crew operations, increased to 2,600 ft (790 m) orVISIBILITY 800 m (2,600 ft) Cat II ...


6

Yes, it is commonly used, especially in large complex airspaces. If two VHF direction finders are installed at sufficient distance from each other, they allow the ATC system to triangulate the position of a VHF transmission. This position is then indicated on the air taffic situation display, which helps the air traffic controller to quickly correlate the ...


6

En-route marker beacons are close relatives of the outer/middle/inner markers used on ILS approaches. Airway markers use the same audio frequency as inner markers, and some older equipment has indicators for airway/outer/middle. Older versions of the FAA AIM discuss marker beacons, but later versions omit them. From Wikipedia: From the 1930s until the ...


6

The value +/-40° is correct, but need to be interpreted. The primary reason of the existence of a "silence" cone is a design choice to increase navaid range. Range and "isotropy" are antagonistic. For the D-VOR there is a second reason: The lack of Doppler effect around the VOR zenith. Detailed case: D-VOR A VOR radiates a signal that can be interpreted in ...


6

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 degrees to all sides, this means that, at 40.000 feet, the signals will be unreliable within about 6 miles from the beacon - which isn't really that much. At lower ...


6

Seattle’s "golf ball" in Discovery Park was once part of the country’s Nike Hercules air defense system of missiles and radars in the 1950s. While most of the structures have been torn down, this golf ball still stands as a relic of the Cold War. Discovery Park used to have an array of radars at its peak. It was a Nike Ajax air defense site in 1953 ...


5

Well, the short answer is that it operates in the same way as VOR except it uses UHF instead of VHF - and is therefore less subject to distortion - and always incorporates DME so a range and bearing are both given. VOR/DME is the civilian equivalent.


5

Short answer: A VORTAC station combines a VOR-DME and a TACAN. It is the result of a cooperation between civil and military worlds to share the same DME (and the navaid place). Civil aircraft use includes accessing the VOR part (civil), the DME part (civil and military), but not the TACAN bearing transponder, said otherwise they access the VOR-DME ...


5

You can buy and legally use TACAN equipment for GA aircraft from Bendix/King, but the system is expensive (close to US\$100,000), relatively heavy and requires rack-mounting.


5

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-bands. If aviation had gotten separate ranges for nav and comm, then that would double the risk of interference from adjacent non-aviation users, plus it would ...


4

Spin the obs 180 so it changes from "To" to "from" then make a 210-220 degree turn(180 plus a 30-40deg intercept) and fly until the VOR radial comes in, then track the VOR.


4

The frequencies are chosen to allow the system to produce a localizer and glideslope 'beam' that provides proportional guidance that can adequately guide an aircraft on the approach. Read through this Question and Answer. As you can see in the description of the beam-forming, the width of the antenna array and the choice of the modulation signals (90 ...


4

When using a DME pair, the location of the receiver can be determined with some accuracy associated. The time measurement is performed with some uncertainty leading to a slant range that is within a ring area (the double circles). Observation When looking at the intersection of the two rings with different positions of the DMEs: The hatched area ...


4

The CDI indicates your desired course. The white circle in the center of the instrument represents your position. If the desired course is to the right of your position, you need to move to your right to rejoin your course.


4

Magnetic, except for places on Earth where it would be truly ridiculous (such as high latitudes). Basically, you want to navigate with one reference or the other, no matter which method you are using, to avoid confusion. Using magnetic reference is somewhat of a legacy: it's natural to use it when your primary method of navigation is a compass. Or even not ...


3

For UAS, the aircraft may be below the service volume of a VORTAC most of the time. Furthermore in the US sUAS are normally line of sight to the pilot so in theory if GNSS is unavailable, the pilot will control visually. Finally the variability and uncertainty of VORTAC is high enough so as to make it impractical for UAS stability, drift and position ...


3

LC/P: Local control, primary frequency, from LC, local control, which is a usual control position in the tower. "The Local Controller is primarily responsible for separating and providing safety alerts to aircraft in the airspace surrounding the airport and aircraft on the active runways" (source) Source PTD: As @Riccati commented, it means Pilot to ...


3

As Ron Beyer commented, it's more of a flat ellipsoid (egg), not a cone. Full Image Another site shows that image: From the United States Standard Flight Inspection Manual, the tolerances are: Minor axis being parallel to approach:


3

The higher the frequency the smaller the transmitter, so fitting the G/S on a small tower near the touchdown zone becomes practical. Compared to the large LOC array at the other end of the runway. [Of] the advantages of using UHF frequencies for glideslope operation is only a small antenna and ground plane is required. As a rule of thumb, the higher the ...


Only top voted, non community-wiki answers of a minimum length are eligible