F.E.A.R. 2: Project Origin
59 Achievements
10-12h
Tour de Force
Mission 4: Rebirth: Destroy a Powered Armor unit in under thirty seconds.
1.0%
How to unlock the Tour de Force achievement in F.E.A.R. 2: Project Origin - Definitive Guide
Shortly after beginning Mission 4, continue until you see a dead soldier in the middle of a chain gate (an automatic shotgun should be near his body). Continue on killing the four stealth soldiers that hang on the scaffolding above. Now prepare, this is where the armor comes up.
Once you walk down the stairs, the armor flies in and the clock starts. Once at the bottom of the stairs, make a sharp left turn and run to the lit area (a stealth soldier may pop up while doing this). Once you arrive, you'll see a Missile launcher laying on the floor. Don't hesitate, immediately pick it up and begin pelting the armor with all five rockets, then pull out your next best gun (I used the Hammerhead I previously picked up) and shoot it until its dead. If you mess up, you can easily pause and reload the last save, and try again.
Here's a video for to those who are still confused, or want to see it in action.
Near the beginning of this mission you will be on the second floor of a building. If you peek over the railing you will see a Powered Armor unit near where you'll need to exit. Nearby there is a missile launcher on a dead body. I would recommend using that first. If you hop down, there is a Laser near where the Powered Armor starts. It is unclear when the 30 seconds actually starts. It could be when you fire at it for the first time, or when it starts shooting at you. In either case, you should have more than enough time to destroy it. See the video below if you have trouble:
Credit to Darkened Night for this video.
Alternate method courtesy of Terminator:
For "Tour de Force" I found a more effective method of getting this trophy was to kill the EPA in the same area where you do the "Dead Weight" Trophy. It's simply really: Make sure you have the Laser handy then when the EPA shows up, hit it with a shock grenade then enter Slow-mo and zap it with the Laser. You will have enough juice left in the power cells afterwards to do "Dead Weight" as well.
I killed the robot very quickly, the main thing is that as soon as you hear mechanical sounds (specific to this robot), immediately run across the bridge behind the rocket launcher. In order to understand where the rocket launcher is, I am attaching a video hint ; the video also shows another method - longer and more expensive.