Welcome to the IREX question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
email@example.com created the topic: ADF To/from Track
Track from ??
ADF needle is in 2nd quadrant so got -48
080-48 = 32
Now the question is is it a To or From
Page 27 of the irex book say that if the answer is in the top half it a TO. However on page 28, the answer is 32 From
If you are using the 'HAT' trick, 'to' or 'from' is determined by the starting point on the ADF dial. If you start at 000°R and move clockwise (+) to the ADF needle, you will obtain the value that must be added to the heading to obtain the 'TO' track. If you start at 180°R and move counterclockwise (-) to the ADF needle, you will obtain the value that must be subtracted from the heading to obtain the 'FROM' track.
In this case, the track TO is 212°M and the track FROM is 032°M.
firstname.lastname@example.org replied the topic: ADF To/from Track
Thanks for the explanation bob. Now I have moved on a bit and have some trouble with en route ADF indications. I can work out the drift and TMG but when it comes to working out which way the ADF needle will move I am getting all confused. Any assistance in this regard will be much appreciated.
For example, tracking from Bathurst to Mudgee W575, Held a heading of 350, What ADF indication will show the track is being maintained. AD1 tuned to Bathurst and ADF 2 to Mudgee.
I understand FPT = 345 HDG is 350, so the ADF indication will be 5 degrees either way. Now how do I work out if it will be 175 or 185 for ADF1 and the same for ADF 2
There's one simple rule concerning the movement of the ADF needle. Providing you hold a constant heading, the ADF needle will always move from the nose to the tail. Or, to put it another way, it will always 'drop' from the top to the bottom of the dial. Therefore the 'tail' of the ADF needle will always 'rise' (move towards the top of the dial.