(a) No person may operate an unmanned free balloon unless --
(1) It is equipped with at least two payload cut-down systems or
devices that operate independently of each other;
(2) At least two methods, systems, devices, or combinations thereof,
that function independently of each other, are employed for terminating
the flight of the balloon envelope; and
(3) The balloon envelope is equipped with a radar reflective device(s)
or material that will present an echo to surface radar operating in the
200 MHz to 2700 MHz frequency range.
The operator shall activate the appropriate devices required by
paragraphs (a) (1) and (2) of this section when weather conditions are
less than those prescribed for operation under this subpart, or if a
malfunction or any other reason makes the further operation hazardous to
other air traffic or to persons and property on the surface.
(b) No person may operate an unmanned free balloon below 60,000 feet
standard pressure altitude between sunset and sunrise (as corrected to the
altitude of operation) unless the balloon and its attachments and payload,
whether or not they become separated during the operation, are equipped
with lights that are visible for at least 5 miles and have a flash
frequency of at least 40, and not more than 100, cycles per minute.
(c) No person may operate an unmanned free balloon that is equipped
with a trailing antenna that requires an impact force of more than 50
pounds to break it at any point, unless the antenna has colored pennants
or streamers that are attached at not more than 50 foot intervals and that
are visible for at least one mile.
(d) No person may operate between sunrise and sunset an unmanned free
balloon that is equipped with a suspension device (other than a highly
conspicuously colored open parachute) more than 50 feet along, unless the
suspension device is colored in alternate bands of high conspicuity colors
or has colored pennants or streamers attached which are visible for at
least one mile. (Sec. 6(c), Department of Transportation Act (49
U.S.C. 1655(c)))