Air-to-air radar does not have a range limit, so say if you spawned an aircraft at wright and teleported to snowstone, as long as you xml'd missileRange, you'd be able to reach it. You would have to spawn your own plane, though, as any naturally spawned aircraft will disappear.

@TheFlightGuySP
Well... This makes making 'beyond visual range' missile a lot easier

@ToeTips @CrestelAeronautics I was referring to air-to-air missiles, sorry.
Air-to-ground radar has limited range, and I'm not sure if there's something you can do to change that.
And yes, air-to-air radar will go beyond 10 miles (in fact I'm pretty sure it's unlimited).

@TheFlightGuySP But the target doesn’t show up at that range

@TheFlightGuySP
What?... Will the radar pick anything up when its farther than 10 miles?

Put the maxRange property in a missile using Overload and set it to a number of your desire.