So Lu, you write the guy who sells static discharge equipment to continue your crack-pot ideas that the sparkles we see on NVG pictures of helos is static electricity discharge. This thread is about 2 years old, I guess you never forget, do you? You are wrong, yet again.
Sailor Vee, the reason why you saw the lights near the beach is that sand is the best stuff for piezoelectric sparkles. Note your comment about wet conditons, which also prove that it is not static electricity. In wet conditions, the static wicks off through the atmosphere easily.
To review: The flashing light seen on rotor blades in NVG's is almost entirely due to the impact of sand/stone particles on the blades when they are struck by the blade. The sand/dust is made of crystals that react to mechanical disturbance by creating light, one of the properties of the electrically bonded crystal lattice. It is this piezoelectric effect that is why a phonograph needle works. The needle is attached to a piece of crystal that has wires attached. As the needle bumps in the record groove, it disturbs the crystal, which emits tiny voltages that are amplified. Those voltages and the tiny light flashes are made by the crystal's internal electron balance, which is reshuffled when the distances between atoms in the crystal change.
Here are two photos that show the effect, please note that the effect is only there when the aircraft has dust around it, because it is glowing dust that we see, not glowing air. Note in the below photo how the particles are flying around the blades, and only at the high speed tips, where the disturbence is enough to make the dust glow? If it were static electricity, it would be a neon glow in the air around the entire blade, not just the tips. In some photos I have seen, the glow can be seen as a discrete bunch of glowing tiny particles. Those particles are the sand glowing extremely faintly after having been struck by the blades. See the dust swirling around reflected in the landing lights, it is this dust that causes the light.
Here below is proof it is not static discharge. The aircraft in this picture is on the ground, where the static electricity is dscharged thru the landing gear, but it still has the glow. No static electricity on the ground LU, None. Note the dust around the aircraft. Dust = sparkly lights, not static electricity = sparkly lights (BTW, the Black hawk has very very good blade electrical bonding straps to conduct lightning away from the blades, the static discharge on the ground is excellent)
Here is a link that explains the effect, and discusses how to do it at home wth sugar cubes and wintergreen lifesavers (I can't make this up!!)
http://www.geocities.com/RainForest/9911/tribo.htm
And to beat this very very dead horse (but this link is worth it!) here is a qucktime movie of a guy scratching a crystal with a nail, the sound is the nail, note the light flashes. Remember, goggles are monochromatic, so the color wont match):
http://mywebpages.comcast.net/jtozou...minescence.MOV
according to the US Army, "The glowing rings are made up of numerous small sparks resulting from grains of sand striking a normally-operating rotor blade, meaning the corona effect can be seen only at night."
http://www.rdecom.army.mil/rdemagazi...dec_boots.html