This Achievement unlocks upon completion of Act 4 of the story when played on Assassin difficulty.
Moving through the cargo area is pretty straight forward; use all the cover mechanics that you've learned so far until you reach the elevator. Once you ascend to the passenger compartment, the fire extinguishers can make short work of your enemies. A direct hit on one will cause it to explode and rip a hole in the fuselage, sucking any nearby enemy out to his death.
After your confrontation with The Immortal, you will progress through a series of quick-time encounters as you climb back through the flames as the plane plummets toward the ground. Go for the head, and make sure you don't miss shooting the bullets that are headed your way, too.
If you have not already unlocked it, you will also earn the following Achievement at the same time as this one: