Confused about ADF intercepts

Personally, I haven't tried ADF navigation in the sim, but I'm guessing its similar to VOR navigation.

This is a post by one of the members here at Flyaway (Bindolaf):

Well, you need to imagine that the VOR station is a sun, drawn by a child. The rays emanating from the center are the "radials". The one on the top of the sun is the 360, the bottom the 180, the left the 270 and the right the 090 radial. All the ones inbetween are 1 degree apart.

These rays mark "roads" in the sky. So, if you take the 090 radial OUTBOUND from the VOR, you will be travelling east, away from the VOR. If you take the 090 radial INBOUND to the VOR, you are travelling west, going towards the VOR station. Make an actual drawing of this on a piece of paper and ponder it for a bit. That is the meaning of inbound and outbound.

You will ask: "If I am inbound to the VOR on the 090 radial, am I not travelling on the 270 radial??".

No! Your heading will be 270, but the radial you're on, the "road" you're on is called 090. Once you pass the VOR station, the "road" is renamed 270 and now you're travelling on the 270 radial OUTBOUND instead of the 090 INBOUND to the VOR. Your direction hasn't changed.

So why bother? Because that's a good way to navigate. Let's say you want to go direct to a VOR called ABC and then you want to fly the 014 radial outbound.

You tune your NAV1 to ABC and fly direct to it. Easy, right? Going "direct" is very easy (just "point and fly") but it's not the usual way. Ok, so now you're approaching ABC and you want to fly the 014 radial outbound. Why? Why the 014 and not "approximately north"? Well, because it's a precision navigation procedure (if I may be allowed the term). Because on that exact radial you will find your next waypoint.

So you approach ABC. Your NAV1 is tuned to ABC's frequency. Now you turn your CRS (or OBS or whatever it is called) [but NOT the heading bug, not the HDG button] so that it shows "014". This has aligned the navigation equipment (not your plane) to show the right radial of the right VOR station. Now you will need to find and fly on that radial. From this point on, read the lesson again and try it or read one of the many excellent tutorials on this site. If you still have questions, I'll be happy to take another stab at an answer.

www.navfltsm.addr.com/ndb-nav-adf-1.htm

www.luizmonteiro.com/Learning_ADF_Sim.htm
🙂

Thanks 99jolegg and CRJCapt, this is the tutorial I am having problems with www.navfltsm.addr.com/ndb-nav-adf-1.htm don't actually understand the formula for it. Maby I am too dumb to figure it out. I will try again.

You said "For example if I am flying 340 Heading and my RBI says 072 and I wish to intercept 125 degree bearing TO the station. How would I do this?"

If flying a unslaved ADF card(C-172), set heading of card to match compass at all times.

1. Turn aircraft to parallel you course TO the station.(125 degrees)

2. The course and the station are to the left (head of the needle is to the left of the nose, still on or about 072). Choose a intercept angle that is 90 degrees or less from course that causes the ADF needle to position to the right of the nose (opposite side from where the course is). Let's choose 60 degrees if we want to intercept the 125 degree bearing TO the station {physically on the 305 bearing}. Intercepting bearings from the station is different. Turn the aircraft to a heading of 60 degrees.

3. As you approach your course, the head of the needle will move downward(toward the tail). When it gets to 125 degrees, you have intercepted the course. Turn your aircraft to 125 and track the bearing. 🙂

The number that the ADF needle points to is the magnetic bearing TO the station, the tail is the magnetic bearing FROM the station.

They used to have fixed card ADF indicators(remained on zero) that required math:
MH+RB=MB---------MH-Magnetic heading
RB=MB-MH----------RB- Relative bearing
MH=MB-RB----------MB- Magnetic bearing
😳

The Time to Station and Distance to Station formula are nice to know but almost never used. I could not even find reference to them in the latest FAA Instrument Flying Handbook. They used to be there but I guess they figured that people didn't use them. I can explain it but I'm tired of typing. 😀

www.faa.gov/library/manuals/aviation/instrument_flying_handbook/

Thanks CRJCapt

This helped me out greatly.

Cheers