Props to the photographer for naming the effect after the soldiers who lost their lives.
(the scene: a firebase in Afghanistan. A platoon of weary grunts are landing in a chopper, returning from a tough mission)
Marine A: Did you guys notice that halo around the rotors when the chopper took off, after we landed at the site?
B: No, douchebag, we were checking our weapons again.
A: That's called the Kopp-Etchells effect.
B: You're going to explain it to us, aren't you?
A: You see, the leading edge of the blades has titanium on it, so ...
B: (chopper lands) Well, here we are! Looking forward to hearing all about this, next mission, douchebag.