Dead or Alive 5

This Achievement is for executing a power-blow on your opponent into the Helicopter behind the tank, which will appear after some time on the stage called "Hot Zone" In order to execute a power blow, you need to have your health taken down to 50% and below, so your health bar begins to glow red. Once your health is glowing red, you must perform the power-blow, which is usually done by pressing and holding back+P+K. Just load up a versus match with a second controller and practice, since it is a bit tricky to execute the power-blow and line it up. As aGundamDownHere said, you can aim with the 'right stick' to line up during slow mo. Since the helicopter isn't there right away, you can either wait some time, since that is how it showed up for me, or you can do as RareWhiteTRASH commented and have controller 2 hit you into the tank, which the helicopter should come shortly after.

Summary
1. Start vs match from the fight menu with two controllers on the Hot Zone stage.
2. Either wait for Helicopter, or have a fighter get knocked into the tank or explosive barrel.
3. Bring down your health until it starts glowing/blinking red.
4. Have controller two aimed towards the Helicopter.
5. Execute a Power-blow and aim with the 'right stick' towards the Helicopter.
After all that, the achievement should be yours.

Okay, here's a quick little video showing how to get the achievement, Tango Kilo November. Short version is you do a power blow at the sandbag wall.