Andy wrote:
On Mar 2, 4:24*pm, Jim Logajan wrote:
Why not? Last I checked, balloon launchers had an equal right to use
the public airspace as anyone else. (In the U.S. part 101 contains
the regulations pertinent to safe operations of balloons.)

The operation described by the OP does not appear to be compliant with
101 subpart D. Perhaps he left out all the details that would make it
compliant. Perhaps he'd post again telling us how he intends to
comply.

I believe you've misread the regulations by not reading 101.1. That is
where it states:

"This part prescribes rules governing the operation in the United States,
of the following:
....
(4) Except as provided for in 101.7, any unmanned free balloon that ...
"

So the "applicability" in 101.1 specifies the criteria that must be met
for _any_ of the remainder of Part 101 to be applicable.

Now in 101.31 in "Subpart D" it states "This subpart applies to the
operation of unmanned free balloons." But that subpart _isn't_ applicable
if the conditions in 101.1 aren't met. (Because it is a _subpart_.) If it
were applicable, then according to 101.33(d), anyone releasing something
as small as a helium party balloon in a town would be in violation of the
FARs.

When properly read, according to 101.1 any unmanned free balloon under 4
lbs of payload that presents suitably large surface areas is not subject
to any Subparts of Part 101.

I've been startled by party balloons when flying power planes in
the Phoenix area. *They wouldn't hurt if I hit one. *I don't relish
the idea of getting a spot through the prop or windshield.

I hate to break it to you, but you are more likely to run into a bird
than a balloon of any sort. Or even another manned aircraft.

Maybe that's because unmanned balloon operations are regulated by 101
subpart D. The flight of birds is, to the best of my knowledge,
unregulated.

A SPOT weighs 209g. It has a density less than water (it's designed to
float.) Might dent the prop or crack the windshield, but can't see it
causing a serious hazard. (You can save the prop from significant damage
but shutting off the engine and gliding. ;-))

And as I said, Subpart D of Part 101 isn't applicable to all unmanned
balloon operations. Small balloons meeting the criteria of 101.1(4) are
not covered by Part 101. The balloon the OP proposes could no doubt be
easily made to comply. And since the OP is a pilot would no doubt perform
the operation as safely as feasible.