Grr ANOTHER Black Hawk question

[Guest AAF]

I just saw some NBC footage of some troops loading into a blackhawk at night time. It looked like the tips of the rotors were lit up. Now, I know that the tips of main rotors are usually colored yellow or something, but they appeared to be glowing. Perhaps they were just reflecting light, or were they in fact emitting light? Anyone more learned on this subject- I would be very grateful to know what the deal is.

[Guest]

Hi,If the footage you saw was shot through night vision equipment, it wouldn't be unusual to see what appears like sparks emitting from the tips of the rotor blades. I can't for the life of me remember what this phenomena is called or how it occurs, but it is pretty neat to see it.Hope this helps,CF-AOA

[KevinAu 441]

Static electricity.

[Guest]

hehe, possibly.Seeing the leading edges of the blades (and the tips) brighter through nightvision equipment is also possible if the rotor has been turning. Friction will cause it to be slightly warmer than the rest of the rotorblade and thus a bit brighter.

[KevinAu 441]

Light amplification nightvision equipment of the kind that you often see on TV that gives the green images do not rely on heat. They operate by amplifying ambient light from sources such as stars, and would not know whether anything was hotter than anything else. Infrared night vision relies on heat, but that is not the basis for images being discussed. Infrared images will be black and white with either white hot or black hot as selected by the operator and would not be able to observe the "ring" of light around the blades.It is static electricity. What you are seeing is a phenomena similar to St.Elmo's fire caused when an object flies rapidly through an atmosphere filled with particles, such as dust. In aircraft, it manifests itself when flying through certain clouds around the cockpit and nose area. Visible only at night becuase of it's dimness, (at least I've only seen it at night) it can appear as an aurora borealis type light display around the cockpit windows or emanating from the nose. With the greater speed at which a helicopter blade whips through the air, it occurs much more readily and will be visible whenever light amplification equipment is used.

[Guest AAF]

Thank you for your input guys! I think it was probably a static electricity phenomenon then- the footage was not through any night time enhanced equipment.