After you infiltrated his headquarters jet with the jet pack there is a sequence.
When the game resumes you have to kill some opponents and Luther will tell you
to put three bombs in the plane. On each side is a ladder. Go up one side then up
the second ladder and go towards the back. There is a mark on the wall in red to
plant one of the bombs. Hold Triangle to do so. Go down the two ladders and kill
the guards that came in. Go to the other side then up the other two ladders. Again,
there is a mark in red where you need to plant the second bomb. Come out and
kill the other guards that entered. Go towards the back where you first came in to
jet in the beginning of the level. Use your Micro-cord gun to latch on to the yellow
pipe on the ceiling. Go all the way back and to find the third final bomb location.
Plant it, then watch the intermission sequence. Stay there and take out your
Sniper Pistol. Snipe the guards that are back by the blue crates. These opponents
are tougher than the last ones you killed, but its easier to snipe them rather than
killing them in close range. Then, get back to the door and go in. Kill the guard
quietly and wait for the enemy to talk to you while you kill the guards that come
down.