The Kopp-Etchells Effect (2012)

<i>The Kopp-Etchells effect was first documented during combat operations in Afghanistan. The photographer Michael Yon named the effect after two soldiers who died there, Koop, a US Ranger, and Etchells, a British soldier. Both were killed in combat in this province of Afghanistan.</i><p>Props to the photographer for naming the effect after the soldiers who lost their lives.

The spontaneous combustion part here feels bit weird; I imagine the phenomenon is more like when you hit metal with angle grinder and sparks fly out, where the abrasive action heats the particles up to ignition point. At least I wouldn&#x27;t call that very spontaneous.

My first guess was triboluminescence, but yeah, pyrophoricity sounds very plausible as well.

The movie scene writes itself:<p>(the scene: a firebase in Afghanistan. A platoon of weary grunts are landing in a chopper, returning from a tough mission)<p>Marine A: Did you guys notice that halo around the rotors when the chopper took off, after we landed at the site?<p>B: No, douchebag, we were checking our weapons again.<p>A: That&#x27;s called the Kopp-Etchells effect.<p>B: You&#x27;re going to explain it to us, aren&#x27;t you?<p>A: You see, the leading edge of the blades has titanium on it, so ...<p>B: (chopper lands) Well, here we are! Looking forward to hearing all about this, next mission, douchebag.