Travel to the airport in the "Islas Intichayes" region (bottom right corner of the map). Then, steal an airplane and fly it into another airplane that arrives (or departs) at the landing strip to get the "A Game Of Chicken" trophy. It does not matter which airplane you are using or flying into. You can also request a fighter jet using airdrop, if you have already unlocked it (which you get by liberating regions).