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