Relative bearing
Join Date: Oct 2010
Location: Styx Houseboat Park.
Posts: 2,055
Likes: 0
Received 0 Likes
on
0 Posts
KISS.
SN. There is some excellent reading 'on the net', there are some gifted instructors in matters aeronautical and there are certainly more patient teachers than I – however. Having watched some struggle with 'concept' I'll try to start you in the right direction. No doubt some of the learned colleagues will take over, refine and add more detail.
The clue is in the name – Relative, in relation to i.e. "considered in relation or in proportion to something else."
Look at your watch face – call 12 o' clock North (360); if you are parked at 12 and the centre of the dial is an NDB (or silo, hill, chook shed – whatever) – you are bearing 360 from that station – the station is 180 from you (Relatively). This leads you to the concept of To – From. Try that for the 1, 2, 3 etc. o'clock bearing To – From. E.g. 3 o'clock is 090 From – 270 To. 9 o'clock is 090 To – 270 From.
Lets park at 3 o'clock and turn the ADF on. Now then, you are pointed North; the ADF needle will always only do one thing – point at the station. So without us knowing where the centre of the clock is we can get 'oriented'. Heading 360, ADF pointy end at 270, so to find the station, turn through the short arc, steer 270 and 'gods willing, weather permitting', eventually you will wind up in the centre dial. If the 'clock' is too hard – think of the VOR 'rose' icon on the Jepp chart: same same..... Once you have it, the aids can be consigned to back of the bag – forever.
Don't muddle a bearing 'relative' to you with a magnetic To- From bearing. The radio mast is at 9 o'clock i.e. 270 relative to you. The track (magnetic) To – From is relative to your track – steering 030 – mast at 270 (R), To 300 - (m). So always ask - relative to what.
I forget the name of it now – think it was called a 'tracks chart', but once you can work out 'where' on the watch dial you are, no matter which way you are pointing, you are always able to work out where you are – in relation to the object of your desire, (Relatively) which is always in middle of the dial (ish).
Hope this is basically what you're after - Handing over to the Pro's.
The clue is in the name – Relative, in relation to i.e. "considered in relation or in proportion to something else."
Look at your watch face – call 12 o' clock North (360); if you are parked at 12 and the centre of the dial is an NDB (or silo, hill, chook shed – whatever) – you are bearing 360 from that station – the station is 180 from you (Relatively). This leads you to the concept of To – From. Try that for the 1, 2, 3 etc. o'clock bearing To – From. E.g. 3 o'clock is 090 From – 270 To. 9 o'clock is 090 To – 270 From.
Lets park at 3 o'clock and turn the ADF on. Now then, you are pointed North; the ADF needle will always only do one thing – point at the station. So without us knowing where the centre of the clock is we can get 'oriented'. Heading 360, ADF pointy end at 270, so to find the station, turn through the short arc, steer 270 and 'gods willing, weather permitting', eventually you will wind up in the centre dial. If the 'clock' is too hard – think of the VOR 'rose' icon on the Jepp chart: same same..... Once you have it, the aids can be consigned to back of the bag – forever.
Don't muddle a bearing 'relative' to you with a magnetic To- From bearing. The radio mast is at 9 o'clock i.e. 270 relative to you. The track (magnetic) To – From is relative to your track – steering 030 – mast at 270 (R), To 300 - (m). So always ask - relative to what.
I forget the name of it now – think it was called a 'tracks chart', but once you can work out 'where' on the watch dial you are, no matter which way you are pointing, you are always able to work out where you are – in relation to the object of your desire, (Relatively) which is always in middle of the dial (ish).
Hope this is basically what you're after - Handing over to the Pro's.
Last edited by Kharon; 15th Jun 2014 at 03:08.
Like Kharon says - keep it simple.
The answer to your questions is: No. There are no simple formulae that you can always apply. The exam questions require you to understand the situation and apply your own logic.
Draw a little picture showing what you know. Put a tiny aeroplane on the picture, oriented appropriately. Now the situation and answers should make sense.
(I real life, and with plenty of practice, most people don't think in exam terms, it will be obvious what/where is going on - but if you don't understand the situation, you won't handle it in real life.)
The answer to your questions is: No. There are no simple formulae that you can always apply. The exam questions require you to understand the situation and apply your own logic.
Draw a little picture showing what you know. Put a tiny aeroplane on the picture, oriented appropriately. Now the situation and answers should make sense.
(I real life, and with plenty of practice, most people don't think in exam terms, it will be obvious what/where is going on - but if you don't understand the situation, you won't handle it in real life.)
