for #3 (the off track scenario)
imagine drawing a line vertically on a peice of paper (your planned track), and a line heading out 8 degrees to the right (your actual track)- you could make this 2nd line 20cm and each cm is equal to one minute if you really wanted to draw it.
this 8 degrees is called Track Error.
now, if you turn left by 8 degrees and projected a line, you would be going straight back up the page. turning left by more than 8 degrees will mean you will eventually get back on your planned track.
if you altered your original heading by 16 degrees to the left, you go past paralleling your track by 8 degrees. the angle that the planned track makes with the new track intercepting it is called the closing angle, which in this case is 8 degrees.
(if however you altered by 24 degrees left, your closing angle turns out at 24-track error = 16 degrees).
note that your track error and closing angle are both the same, so for the sake of simplicity (nil wind), you will get back on track in the same time from your present position as it has taken you to get from point A to your present position.
a closing angle greater than your track error results in you getting back on the planned track quicker than the time it has taken from your previous fix to present position; consequently the reverse is true- a closing angle lesser than your track error results in you getting back on the planned track longer than the time it has taken from your previous fix to present position.
once back on track, if you turn 8 degrees right you will then go straight back up the page and stay on track.
the heading to fly after intercepting the planned track is your original heading plus your track error.
i hope that clarifies it.
Last edited by witwiw; 7th Sep 2006 at 11:07.