Good afternoon all...

I hope these Links will answer your question "yancovitch"...
http://www.ruudleeuw.com/dc-3_page_2.htmhttp://www.youtube.com/watch?v=o2IaMFOyyUUhttp://www.michaelprophet.com/News_articles/Safari.htmlAn aircraft that depicts a black nose usually has radar of some type.
If the aircraft is running, the beacons are on it is not a good idea to look directly at the nose of the aircraft.
The radar should be off when the aircraft is on the ramp however if a radar test is being done there is an operator in the aircraft along with a spotter. The area must be posted to warn anyone that the radar will be tested.
Stay away from the aircraft...simple as that...

Radar can cause medical problems and most airports will only allow certain testing and then the aircraft should actually be facing away from the hangar line and people.
An Electronic Warfare Aircraft with a radome on top, if the aircraft is on the ground and the radome is revolving, this does not mean the radar is on.
The military and commercial operators have rules about the use of radar. I am not a specialist in any way shape or form on this topic, I can only pass on what has been told to me.
I would think there are Maritime Rules and Regulations concerning the operation of radar also. When I watch private yachts or commercial vessels comming into harbour here there units are not rotating.
Cheers...Happy Landings...Doug