It's suddenly dawned on me that perceiving an attack by ground fire when riding in a helicopter is not a straightforward process. If you see muzzle flashes winking at you at night or from the shadows of thick vegetation, that's pretty obvious you're in someone's sights. But if you don't see any signs of drawing ground fire, you could be under attack and not know it. The passenger compartment of a UH-1 with both cargo doors open is a very noisy environment, with the screaming whine of the jet engine and thunderous "WHOPPA-WHOPPA-WHOPPA" of the spinning rotor blades drowning out virtually all other sounds. But it's still possible to hear a gunshot if it's aimed right at you; it just might be subtle sounds that you could easily ignore if you're not listening closely. A single gunshot might sound like "bzzpop" if fired from extended range, or like BzzzPOP! if fired from a much closer range. And in addition to the sights and sounds of a gunshot, you might actually feel a slight breeze as the bullet passes by your nose. You need all of your senses working at peak performance to survive encounters with ground forces when you're in a lightly-armed slow-moving helicopter in Indian country!