This achievement requires that you make three killing streaks of at least 15 kills. Although several websites claim that this achievement must be earned in multiplayer game modes, this is not the case.
The easiest way to earn this achievement is to play through the Cairo mission, and get a series of chain kills from destroying the parachutes. Remember to be aware of where your targets are - don't destroy 5 parachutes, and not know where to turn to next!
Also, once you have earned a 15 kill streak, stop, and let the "timer" reset, so that you can then start on a new set of parachute targets. Following this method, or one very similar, should assure you the achievement in no time at all.