The radar is divided in two different sections:
a) Sector radar - the bars in the upper left corner of the sector, they show quantity of friendly and enemy planes in that sector.
b) Tower radar - this has unlimited range for friendly planes and a range limit of 12.5 miles for enemy planes and shows exact plane location.
You can fly under radar coverage (no tower radar icon, no sector indicator afaik) by flying below 500ft AGL (could be less, you can check this with country mates if they can see you on the radar with the .wingman command). What's missing here is a reduced icon visibility for very low flying planes. Currently you get the neon sign indicating you're a dead 47 soon if any con is within 9k range, regardless of alt.
There are two sources for radar that can be killed: Tower based radar for enemy planes can be shut down by hitting the towers at fields, and all radar including sector indicators, friendly and enemy positions are affected by a destroyed HQ.
Az
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Azrael
XO
487th BG (Heavy)'The Gentlemen from Hell'
[This message has been edited by azrael (edited 12-21-1999).]