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NikhilMehta
13th Mar 2008, 14:04
hi, i need to know about the ADF needle hunting. Basically want to know that amongst the error due to Thunderstorm effect (static) and the Night Effect(sky wave interference), in which case the hunting of the needle will be more pronounced and why? For what i know that due to the thunderstorms there is static (free electrons) of the same intensity and the needle points towards them and in case of Night Effect the waves get reflected from the ionosphere and come back towards the loop from top to bottom, creating a phase difference with the ground waves hitting the loop from left to right. Both situation i assume can cause needle hunting, but like i said, which one will be more pronounced?

londonmet
13th Mar 2008, 14:09
Taking a punt there but I believe thunderstorm effect would be more pronounced.

L Met

coodem
13th Mar 2008, 15:22
I agree, thunderstorms

EK4457
13th Mar 2008, 15:38
Yes, thunderstorms I seem to remember will affect the ADF more and cause it to give spurious readings.

Not sure about it being called 'needle hunting' though. I thought that was a poor method of ADF (or VOR/ILS) tracking where a pilot 'follows the needle' instead of a wind corrected HDG and ends up making a sinusoidal path about the track required line.

Could be wrong though....

EK