Throw a flash bang into the first group of enemies, grab a shotgun. Run towards the side where the airplane opens up and hide behind cover is just barely taller than you when you crouch and throw a flash bang. Use your shotgun. Run up the stairs, before heading into the next room throw a flash bang, and clear the room. After clearing the room, throw a flash bang into the next area and clear it. Lastly, watch out for the last guy before the "final boss", he has a shotgun so react quickly. Aim for the head.