Okay, so I was playing the demo to Just Cause 2, and I'm riding my motorcycle down the dirt highway toward the colonel. I'm shooting at the baddies intensely, using the little submachine gun to the fullest. As I'm bowing up cars that pop up next to me, I find that a helicopter is shooting at me with rockets and a gigantic Machine gun. I try to evade it for about ten minutes, but to no avail. It gains on me, I turn sharply off the road, then jump off of a plank of wood on a little stand to fly over a building, jump off, open my parachute, then latch on to the helicopter as it flies by.
Of course, I think, "Oh hey, that was pretty slick. I got this covered." So I shoot the guy on the side, and enter the helicopter by throwing the guy out inside. I fly around shooting enemies on the ground, then three helicopters fly up behind me and shoot me up a ton.
I try to fly away, but they blow up the helicopter just as I jump out and billow my parachute again. I fly down to the ground slowly while trying to grapple the enemy helicopters, but instead, I just land on the ground, then try to run away. By this point, my health is down to about 30%, but I keep trying to run. The helicopter shoot and shoot at me, but I attempt to dodge each time. I start frantically firing my grappling hook at the helicopters again, attempting to latch on and take one over, but my mashing buttons kind of messed up the aiming just a bit. The helicopters catch up to me, and I'm screaming at my friend, "I NEED BACKUP, I NEED FREAKING BACKUP!" But he just shakes his head menacingly as my character gets pelted by bullets, and in the end, dies by a rocket blast that shoots him up into the air, then gets chopped up by the helicopter blades.

The moral of this story is, bring backup.