Bela P. Havasreti wrote:
Bingo. The feds hold their cards close to their chest on this
one. It's congested if they say it's congested, and not if they
say it's not. Unfortunately, there is no way for the average
aviator to figure out which is which by reading and interpreting
the regs....

Exactly. And if you have an accident or someone complains, then it can
easily become "congested" :-)

Now if Mxsmanic says "well that's stupid, how does anyone know?", then
he's right. It's one of the zillion little you-know-it when-you-see-it
kind of rules in aviation. Like the vague "familiar with all
available information" rule. (14 CFR 91.103)

===

That said, here's some digging on "congested areas" that sheds a little
light:

Letter from a state aviation counsel:

http://www.aopa.org/epilot/redir.cfm?adid=8604

"There is no standard definition of what is a 'congested area' or 'open
air assembly of persons', but case law has indicated that a subdivision
of homes constitutes a congested area, as does a small rural town"

===

"General Aviation Operations Inspector's Handbook, Order 8700.1".

http://www.faa.gov/library/manuals/e...spectors/8700/

From that (btw, check out Chapter 56, ramp inspections), we go to
Chapter 102. Although it's about helicopter load operations, it seems
to have the only definitions I've seen, vague as they a

http://www.faa.gov/library/manuals/e...a/2_102_00.pdf

"The congested nature of an area is defined by what exists on the
surface, not the size of the area. While the presence of the
nonparticipating public is the most important determination of
congested, the area may also be congested with structures or objects.
An area considered congested for airplane operations could be equally
congested for helicopters. If an airplane flying over a congested area
at less than 1,000 feet above ground level (AGL) is in violation of 14
CFR § 91.119(b), the area may also be a congested area for a
helicopter conducting external load operations. However, the most
important word in this concept is 'over.' Helicopters can operate over
relatively small uncongested areas because of their maneuvering
abilities.

(b) Densely Populated Area. Title 14 CFR §§ 91.313 and 133.45(d) use
the term "densely populated" area. Those areas of a city, town, or
settlement that contain a large number of occupied homes, factories,
stores, schools, and other structures are considered densely populated.
Additionally, a densely populated area may not contain any buildings
but could consist of a large gathering of persons on a beach, at an
airshow, at a ball game, or at a fairground. NOTE: While the presence
of the nonparticipating public is the most important determination of
congested, this definition also applies to structures, buildings and
personal property. The congested nature of an area is defined by what
exists on the surface, not the size of the area."

Cheers,
Kev