Kamov K-27

Here's a Russian Kamov K-27 helicopter on an American aircraft carrier. It has two sets of blades turning in opposite directions, kind of like the American Kaman K-Max, except these rotors are on the same axis where as the Kaman is arranged more like an egg-beater. This makes for very complicated control linkage.

Might be a Ka-50 Rotor Hub
Might be a Ka-27 Rotor Hub
Hard to tell, when you can't find the original.

This looks like a design battle between two Kaman and Kamov. Kind of reminds me of our own helicopter designers Sikorsky and Piasecki. Piasecki was Polish. Kamov and Sikorsky were Russian. Kaman is an American, though his name is very similar to Kamov, and his being in the same racket as these other three guys makes me think he's probably got some Eastern European heritage as well.

Is this design really any good? It looks awfully complicated. However, it seems to be fairly reliable. The Russians have several hundred that they have been flying for years. It has an advantage over single rotor choppers in that it does not have the long drive shaft to the tail rotor, which seems to cause more than it's fair share of problems. It has an advantage over the K-Max in that rotor blades don't come as close to the ground when it is on the ground. The K-Max rotors are tilted outward so they can interleave. The control linkage for the K-Max is going to be just about as complicated for this one, after all they still have to control two rotors, and the linkages for the two need to be connected, which means more complications. The transmission for the Kamov would be more compact than the one in the Kaman. Not any less complicated, but more compact.

More Kamov photos here.

Update December 2016 replaced missing picture.
Update December 2018 replaced dead link to photo album with generic Google search.