Get to the Chopper
The helicopter is no doubt prized among gamers, as it provides an easy escape route (provided the police don't take to the air, too). Even though it's not bulletproof, the helicopter can withstand a fair amount of direct gunfire. You have to complete all the story missions to get it. After completing the missions, go to the Escobar Airport and head to the ticket office. Round the corner from the office to see what looks like a tunnel for an underground garage. Take it all the way to the end, past the planes, and keep heading east. At the very end of the runway sits the prized helicopter.
And Get Ammo While You're There
The helicopter provides plenty of transportation ability, as long as your destination has a helipad. If not, you may attract some unwanted attention in the form of gunfire when you land on the street or parking lot. If you haven't already, get armed to the teeth without having to buy weapons by pressing left, right, X, up, down, square, left, and right for the first set of weapons. Change the third and sixth step to either the circle or triangle to obtain the other weapons.
Another Handy Vehicle
The helicopter may help you fly away from less than desirable situations, but there may be times when you're stuck on the street and need to fight your way out. If so, press up, L1, down, R1, left, L1, right, R1 to automatically spawn the Rhino armored tank. While the tank withstands all gunfire, and can dish out as much as it gets, it moves slow so you'll have to avoid getting stuck on inclines, which allows your enemies to pull you from the tank.