As you head back to the Enterprise you will be ambushed by an Ace Pilot and a few other planes. Now this Ace pilot is smarter and more agile than any other pilot. He will do spins into the air. He will dive under you and instantly turn to get behind you to shoot. But just like previous planes and other health bar related enemies they can drain rather quickly if you hit him well enough.
The other pilots with him also fly a little better but are still just standard among pilots.
Once you kill the ace pilot the achievement will unlock.