The VOR transmitter has inbuilt systems to check its accuracy. If it drifts by more tha a degree or two (can't remember the exact figure) it shuts down.
What bearing did you expect to be using at Kirkbymoorside? What was the actual bearing on the OBI that centred the needle?
<<edit: Ground equipment accurate to ± 1°. Airborne equipment meant to be within ± 3° to be certifed as acceptable. Max error, therefore, ±4°. Do this with two receivers (to do a position fix) and you could be in the region of 8° out. If 60 miles from the beacon, that puts you 8nm away from your 'fix' and, if travelling at 120 knots groundspeed, and taking two minutes to do the fixing and plotting, you will have flown 4nm from where you started. VOR fix gives you a rough indication of where you used to be - not where you are.
Not much to do with the original question - I just got carried away after saying ±1°.>>
Last edited by Keygrip; 26th Aug 2005 at 11:44.