Here is the full list of all 20 Unmanned helicopter achievements.
You must launch the game
You must be in the game for two hours
Completed the 1st level
Completed the 2st level
Completed the 3st level
Completed the 4st level
Completed the 5st level
Completed the 6st level
Completed the 7st level
Completed the 8st level
Completed the 9st level
Completed the 10st level
Completed the 11st level
Completed the 12st level
Completed the 13st level
Completed the 14st level
Completed the 15st level
Completed the 16st level
Completed the 17st level
Completed the 18st level