Power Lines..

How high must they be to fall into the FAA's definition of
obstructions?

--Dan


Ron Natalie wrote:
Doug wrote:
There are some awesome powerlines spanning valleys in Idaho near the
Snake River and let me tell you they are a loong way up from the bottom
of the valley, easily 500', probably 1000' or more.... Some of the
lines are on the sectional. I've never seen a power line on a sectonal
marked with obstruction footage, but they might exist.

john smith wrote:
In article ,
Ron Natalie wrote:

Power lines are marked for use as visual landmarks, NOT as obstructions.
Unless it is a catanary spanning a valley.


I was assuming we were talking the normal chart power line symbol
(these look like little power line towers with lines connecting
them). Where the towers themselves are obstructions one of the
obstruction symbols (inverted V with a . in it) will be shown.
An example around here is on the Potomac river just north
of Quantico, VA (more apparent on the Washington/Baltimore
TAC chart than the Washington Sectional).

In article .com,
"Doug" wrote:

I've never seen a power line on a sectonal
marked with obstruction footage, but they might exist.

Several years ago, the FAA added the symbol for a catenary by
highlighting/darkening/thickening the line where it is strung across a
valley.

Ron Natalie wrote:
Dan wrote:
I've seen power lines marked on sectionals. How high are the highest
major power transmission lines? They look quite high from the ground,
but there's not much to give perspective.

--Dan

Power lines are marked for use as visual landmarks, NOT as obstructions.

No kidding. You shouldn't even be worried about power lines, unless
you're spraying or doing some strange kind of helicopter work.

Emily schrieb:

No kidding. You shouldn't even be worried about power lines, unless
you're spraying or doing some strange kind of helicopter work.

Or unless you're flying in the mountains, where they become too often
deadly traps to flatlanders who don't even worry about them.

Stefan

Or where powerlines cross a river valley, airplanes
following the valley can often be well clear of the river
and still be caught by the powerlines strung from towers on
the ridges on each side.



"Stefan" wrote in message
. ..
| Emily schrieb:
|
| No kidding. You shouldn't even be worried about power
lines, unless
| you're spraying or doing some strange kind of helicopter
work.
|
| Or unless you're flying in the mountains, where they
become too often
| deadly traps to flatlanders who don't even worry about
them.
|
| Stefan

Jim Macklin wrote:
Or where powerlines cross a river valley, airplanes
following the valley can often be well clear of the river
and still be caught by the powerlines strung from towers on
the ridges on each side.

Or even worse, kill other people.

http://en.wikipedia.org/wiki/Cavales...e-car_disaster

"The restrictions in effect at the time required a minimum flying height
of 2000 feet (600 m); the pilot said he thought they were 1000 feet (300
m). The cable was cut at a height of 360 feet (110 m)."



Leonard

Ocassionally I see one with obstruction lighting. I'm guessing those
are over 200 feet and the rest under 200.
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because we fly, we envy no one.


Dan wrote:
I've seen power lines marked on sectionals. How high are the highest
major power transmission lines? They look quite high from the ground,
but there's not much to give perspective.

--Dan