TACAN offset for low visibility landings

[A2597]

So I know the F18c doesnt support ILS, but does TACAN. The issue then is that the TSCAN beaton can be a couple hundred feet off center of the runway. Is there a way to adjust it to be on center? Like a course offset?

[Lv100Latios]

Someone might have to correct me on this, but from what I understand, the TACAN is not meant to have an approach down the ground and instead requires minimums that have to be met in order to actually be able to land. In essence: if you cannot see the runway at x altitude at y distance from the beacon, you must go around and probably find somewhere else to land.

[Emmy]

^^^ Correct ^^^

 

TACAN is not a precision landing aid. It’s a homing beacon with which you can set up to follow a published approach to a given set of minima.

[AMEDooley]

It’s something like 800ft at 3/4 of a mile if memory serves

[Eagle7907]

TACAN offset for low visibility landings

 

I would just make a waypoint over the threshold use same magnetic course and use simple 3:1 arithmetic to 3/4 mile final. That will be just as good as RNAV GPS approach. Of course I wouldn’t do that over any mountains or known obstacles.

 

 

Sent from my iPad using Tapatalk Pro

[Robin_Hood]

However, a TACAN Offset function would be useful for direct navigation information to NAV points, but it doesn't seem that there is one in the F/A-18C.

For the record, I've seen TACAN approaches with 500 ft minimum, and even 350 ft I believe (now that is pretty for a non-precision approach).

Edited March 2, 2019 by Robin_Hood

[A2597]

Ok, so how would one do a proper instrument approach to a land base in an f18c?

The landing plate does give latitude and longitude, runway course, etc, but no idea if that's on the runway, or just for the airport.

 

So what would be the "real" way to do an instrument approch?

[Emmy]

You follow the headings and altitude(s) laid out on the published approach.

[SmilingBandit]

You follow the headings and altitude(s) laid out on the published approach.

Long story short, this.

 

 

For a longer story let's look at Fort Wayne, Indiana's VOR approach.

https://aeronav.faa.gov/d-tpp/1903/00156VT23.PDF

 

 

For this one you will be vectored until you intercept the 224 radial. Looking at the bottom right we see the altitudes that one would have to stay above (indicated by the line underneath) as you cross each DME distance (shown by the bulging rectangles above the glide path line) until you get to the decision height shown on the far bottom (the category in this case are based on approach speed). For a cat A or B group that would mean that by the time you hit 1.8 miles you can't go below 600' until you see the airfield environment. At 0.5 miles you perform a missed approach.

 

 

Note: Not an instructor, certainly not your flight instructor. This is for game use only.

[Robin_Hood]

The quick and dirty way: you know the runway heading (at least approximately from it's number), so with the TACAN you can line-up in the correct axis. Then, you can come closer and descend, until you can see the airport (ie. you've gotten Under the cloud ceiling, or close enough to see through the fog). When you have the runway in sight (or the the lights*), you can just complete your landing visually.

* When you contact ATC to land they should turn on lights.

 

 

Of course the correct way is to use a published TACAN approach to line up and comply with the minimum descent altitude