Basic Training - Navigation & Bullseye - TACAN navigation

Written by
Dean "Bunch" Wright

[ Part 1: Navigation & Bullseye | Part 2: TACAN Navigation ]

Introduction.

What is Tacan and when would we use it?

Tacan (tactical air navigation) is essentially a backup navigation system to your main mission computer. In normal flight we use the MFD and HUD steering cues for Navigation. However if our plane is damaged in some way and we lose the use of these systems, Tacan can be used to navigate back to our home or divert airfield. Tacan can be used for a variety of other navigational tasks but unless you're interested in learning these functions navigating home when damaged is likely to be the only time you would use Tacan. A beacon based at an airfield emits a signal, which your Tacan computer can home in on.

Navigating to Airfields with Tacan.

Now for the good news – Tacan is real easy to learn and use. Lets take a look at the cockpit information. We only need concern ourselves with 3 functions on the Tacan panel.

CNI Switch
The default position is UFC (Up Front Controls), which means navigational information will come from your main mission computer, the normal HUD steering cues etc.

If you move this to the BACKUP position the navigational information will come from your Tacan system.

TACAN Function Knob
The default position is AA/TR (Air to Air / Transmit & Receive). This is to receive information from airborne tankers.

The T/R position (Transmit & Receive) will pick up signals from a ground based Tacan station like airfields.

TACAN Station Selector
The default setting is 106X, which will pick up information from the Tacan station based at Kimpo International airfield. You can click on these numbers to dial in the Tacan station you wish to receive navigational information from. Many of the cockpits available will have this information on the kneepad. Alternatively appendix C at the back of the F4 manual has this information.

HSI (horizontal situation indicator).

Now lets take a look at the HSI.

Mode Switch
To view your Tacan information on the HSI you will need to put this in the TCN position.

Miles From Selected Tacan Station
This is self-explanatory – it displays the amount of miles from the currently selected Tacan station.

Red Arrow
The red arrow is pointing in the direction of the currently selected Tacan station. Simply line up the little picture of the plane (in the centre of the HSI) with the red arrow. You will then be flying directly to the selected Tacan station.

Summary.

Follow these simple steps to navigate to an airfield using Tacan.

• Set the CNI switch to BACKUP

• Move the TACAN Function Knob to the T/R position

• Dial in your selected Tacan station on the TACAN Station Selector

• On the HSI, move the Mode Switch to the TCN position

The distance from the selected Tacan station is now displayed and a Red Arrow will be pointing in the direction of the selected Tacan station.

Practical use.

During your mission brief, it is a good idea to jot down your home plate and divert field Tacan channel in case you lose your primary navigational system. This will help you to return to a friendly field quickly and accurately.

Further Tacan Functions.

As stated earlier, Tacan can be used to obtain a variety of other navigational information. The CNI function is useful for lining up with the runway and the Tacan ILS is useful for getting on the correct glide slope (this does take some practice but it can make the difference between a good landing and a bad one when you’ve got no HUD). If you wish to study these other functions, the F4 manual covers the subject quite well; training mission 10 pages 3-7 to 3-13 is excellent for learning this skill.

Download a document with all Tacan channels listed.

[ Part 1: Navigation & Bullseye | Part 2: TACAN Navigation ]