No person may operate an unmanned free balloon --
(a) Unless otherwise authorized by ATC, below 2,000 feet above the
surface within the lateral boundaries of the surface areas of Class B,
Class C, Class D, or Class E airspace designated for an airport;
(b) At any altitude where there are clouds or obscuring phenomena of
more than five-tenths coverage;
(c) At any altitude below 60,000 feet standard pressure altitude where
the horizontal visibility is less than five miles;
(d) During the first 1,000 feet of ascent, over a congested area of a
city, town, or settlement or an open-air assembly of persons not
associated with the operation; or
(e) In such a manner that impact of the balloon, or part thereof
including its payload, with the surface creates a hazard to persons or
property not associated with the operation.