A power transmission line (probably 115 or 138 kV) runs along the Casper Creek (f.k.a. Casperkill) and through the Vassar campus beyond our back yard, which accounted for a loud roar one morning:
The pilot hovered above each pylon long enough for the inspector seated in the open door to do whatever needed doing:
A casual image search suggests it’s an MD520N (N = NOTAR = “No Tail Rotor”) helicopter. Although the NOTAR back end produces much less noise than an exposed rotor, it was plenty loud enough a few hundred feet away.
Folks who know more than I do about helicopters pointed out the tail rotor I didn’t see. Here’s a tight crop from another image with the rotor in plain view:
Just another day at the office …
The Smell of Molten Projects in the Morning 
Comments
7 responses to “Helicopter Power Line Inspection”
The NOTAR MD500 has a thicker tail boom than the helicopter in your picture.
I just updated the post with a better picture: it’s definitely not what I thought.
Good catch!
I know a little about helicopters. That image shows an MD500 ( a ‘D’ model I think) – it has a tail rotor. You can see one blade just peeking above the tail boom.
The NOTAR (MD520N) has a much thicker tail boom to enclose the fan and other hardware to produce the variable thrust that provides the anti-torque moment.
I don’t think I can post an image, but here’s a link:
https://commons.wikimedia.org/wiki/File:Md500n.g-smac.arp.jpg#/media/File:Md500n.g-smac.arp.jpg
:)
Right you are!
Turns out the rotor shows clearly in only one of my pictures and, of course, it’s one I didn’t use, but now it’s in the post.
Thanks!
Plantation Pipeline flies a segment of their line every day with good weather. They’re looking for leaks, yes, but mostly they’re on the lookout for backhoes!
And, perhaps, evidence of a suspicious run of pipe off into the woods.
That HV line has glass insulators on the pylons where it turns a corner, so I suppose they’re looking for damage caused by idiots with firearms. :sigh:
Segments of that pipeline are running 3000 psi – drill a hole and it will diesel when it hits the air. :-)