How do you pop Flares Battlefield 3

You can pop flares from a jet or heli when you unlock them after playing for a while and then you press r1 to use them after equipping them at the deployment screen. An easy way to get points to get the flares is by finding a good pilot and sitting in the gunner seat whilst you're getting a few kills yourself the pilot will probably have heat seeking missiles and flares so you can mostly just watch. The assisted points rack in. I found a good pilot and unlocked heat seekers and flares in just one game.