PDA

View Full Version : VORTAC's VOR/DME's?


steggers
29th Aug 2008, 17:02
Hi guys. I'm hoping to go out to Florida tomorrow to do some hour building and would like to know what the difference is between a VORTAC and a VOR?

Dream Land
29th Aug 2008, 17:31
A VORTAC is a VHF Omni Range and Tacan (UHF) co-located, the tacan has a channel for military, they will then receive azimuth and DME, for civil use you will select the VHF frequency and if you have DME equipment you will receive it automatically.

steggers
29th Aug 2008, 17:43
Can you use the VORTAC in the same way as a VOR then?

BEagle
29th Aug 2008, 18:13
Yes.

And if your aircraft has DME, a VORTAC will give you bearing AND range!

UncleNobby
30th Aug 2008, 02:21
If you're aircraft does not have DME then there if no difference (ie azimuth only). If it has DME then it also gives you slant range to the station (same as a VORDME but it's a military installation). You can also get TACAN only stations that does not have VOR but can still be used as a DME (maybe a dual-use civilian and military airport). Look at your sectional to see how they are represented on the chart (skyvector.com)
This is basic stuff but whatever.
Added bonus...Some VOR stations have HIWAS (Hazerdous in Flight Weather Advisory Service) that gives you Wx info that requires immediate dissemination - handy if you're in Florida with the threat of T-Storms. Look for the little H in the left hand corner of the ID box on the sectional. Tune into the VOR and hit ident to listen to the recording.

bArt2
30th Aug 2008, 07:21
A VORTAC is a combination of a VOR and a TACAN, that are installed at the same location.
The frequency that is written next to it is in fact the VOR frequency that you can dial.
The channel that is written next to it is the TACAN frequency that only military aircraft can dial.
A TACAN station always has a DME, which works in the same way as a civil DME therefore if you carry DME equipment in your aircraft you can also tune to it and you have the same information as a VOR/DME.

A VOR and a TACAN work in a different way but the cockpit indication is the same, both send out radials. The VOR works in the VHF range (108-117.95 Mhz) while a TACAN works in the UHF frequency range.
A VOR station is in fact a very large (I estimate about 20m radius) fixed installation while a TACAN is quite small and can be made mobile.
The TACAN has as advantage that it is small and can be moved around, which is very interresting for the military. The disadvantage of a TACAN is that it can have a fourty degrees azimuth error and the cone of confusion is much larger than that of a VOR.

A TACAN looks like a barrel, in the middle (inside the barrel) you have a fixed antenna, and another antenna rotates around it.

In a VORTAC the TACAN is often installed on top of the VOR.

On the picture below you see a VORTAC, the VOR is the large circular construction and the TACAN is the white barrel on top.

http://upload.wikimedia.org/wikipedia/commons/thumb/9/93/VORTAC_TGO_Aichtal_Germany_01.JPG/800px-VORTAC_TGO_Aichtal_Germany_01.JPG


Picture courtesy WIKIPEDIA

Bart