Like you AV8, I have had the ADF taught to me in lots of ways. OZ, yes for working out your QDM back to the beacon then transposing the ADF needle works a treat and keeping it simple is the ticket!
I’m currently using the following method with my IMC student. It works for him.
Point 1: If you have got a moveable card to the ADF dial up 360 at the top of the instrument. Now don’t change this and use it like a fixed card ADF
Point 2: The head of the needle always shows you which way to turn, so if it is left of 360 then you turn left, if its right of 180 then you turn right.
Point 3: The head of the ADF needle always falls down the face of the instrument
Point 4: To get on to a desired QDM to a beacon, turn the aircraft to that QDM and then correct as per point 5. This is a very PPL thing to do; CPL chaps should be turning straight to a heading to gain the inbound QDM. (ie. fly an aeroplane with an RMI). But this method works!!
Point 5: When you are flying your correct heading and the needle shows you an error, double the error in your correction to get back on your desired QDM/QDR, to/from the beacon.
Here are some examples to illustrate:
Inbound to a beacon on a heading of 100. ADF shows 5 degrees right (ie. 005 on the ADF). So to get on our 100 inbound QDM turn right 10 degrees correction, so that’s 110 to fly. We know that we are back on our 100 QDM when the ADF indicates 10 left (ie. 350 on the ADF). Now turn back to your heading to maintain the 100 inbound QDM.
And here’s another:
Outbound from our same beacon maintain a QDR of 100 (that’s a QDM of 280 ie the same ‘radial’ as in the previous example but outbound). ADF shows 5 degrees left (ie. 185 on the ADF), so to get back on our desired QDR, turn left, double the error giving 090 to fly. Now we are back on our desired QDR when the ADF indicates 10 left (ie. 190 on the ADF). When this happens turn back to your heading to maintain.
Point 6: If you get confused just change your heading to your desired QDM/QDR and then correct it as per point 5.
Point 7: Don’t forget to keep re identifying the NDB morse ident. CAA trappers love it when you do that!
This might all sound confusing, but once you have the concept it is easier to use in the air than that + - + - stuff.
If you’re still confused try drawing the above examples out.
Have fun,
Vigi
[This message has been edited by Vigilant Driver (edited 01 March 2000).]