Here is the full list of all 23 Frequent Flyer achievements.
Get total score of 500000
Fly 1000 games!
Fly 500 games!
Fly 100 games!
Get total score of 250000
Destroy 50 minelayers
Destroy 50 flying bombs
"Sabre" plane unlocked!
"Il" plane unlocked!
"Spitfire" plane unlocked!
"Me 262" plane unlocked!
"Messer" plane unlocked!
Get 5000 score in one game (infinite/organized mode)
"Pe-8" plane unlocked!
Get total score of 50000
Destroy 50 scout planes
"Mustang" plane unlocked!
Destroy 100 rockets
Destroy 100 zeppelins
Get 500 score in one game (infinite/organized mode)
Get 1500 score in one game (infinite/organized mode)
Get 2500 score in one game (infinite/organized mode)
"Lock" plane unlocked!