Here is the full list of all 45 Aces of the Luftwaffe achievements.
Shoot down 5000 planes.
Bomb 6 Axis factories with the Allied bomber. (Mission 2-1)
Defeat General Neumann.
Complete all Missions of Chapter 1.
Collect 1000 Medals.
Shoot down 50 jet planes. (Mission 1-3)
Down half a dozen heavy bombers. (Mission 1-3)
Kill a dozen Messerschmitts! (Mission 1-1)
Kill 300 Focke-Wulfs. (Mission 1-1)
Kill 1000 foes!
Collect 48 Power-Ups.
Dance, dive bombers. Dance! (Mission 1-2)
Kill three Heinkel Bombers. (Mission 1-2)
Rack up 25000 kills!
Bomb 100 targets.
Bomb 500 targets.
Bomb 2500 targets.
Grab 5000 Medals.
Need! Need! Need!
7777 confirmed Focke-Wulf kills.
1337 confirmed Me262 kills.
88 confirmed Ju88 kills.
666 confirmed Ghost kills.
Bomb all the Axis panzers invading France. (Mission 2-2)
Bomb 30 AA gun nests! (Mission 2-3)
Shoot down all three of the Super Planes. (Mission 2-3)
Defeat Major Kohler.
Complete all Missions of Chapter 2.
Shoot down 25 Bf110 planes. (Mission 3-1)
Kill a Fiat BR.20 bomber. (Mission 3-1)
Bomb 40 AA gun nests! (Mission 3-2)
Whatever those things are, kill them. (Mission 3-2)
Rumor has it there's over 70 airborne. (Mission 3-3)
Defeat Oberst Müller.
Complete all Missions of Chapter 3.
Stay stealthy the entire mission. (Mission 4-1)
Shoot down 10 Zeppelins. (Mission 4-2)
Defeat the Mad Scientist. (Mission 4-4)
Complete all Missions of Chapter 4.
Shoot down 15 Heinkel planes. (Mission 5-1)
Bomb 3 Axis Airbases with the Allied bomber. (Mission 5-2)
Shoot down all 7 Ghost planes. (Mission 5-2)
Evade all Mines. (Mission 5-3)
Defeat Commander Meiler
Complete all Missions of Chapter 5.