Here is the full list of all 16 Chopper: Attack helicopters achievements.
Island map passed for Mi-8
Island map passed for Mi-24
Island map passed for Mi-28
Island map passed for Ka-50
Desert map passed for Mi-8
Desert map passed for Mi-24
Desert map passed for Mi-28
Desert map passed for Ka-50
Winter map passed for Mi-8
Winter map passed for Mi-24
Winter map passed for Mi-28
Winter map passed for Ka-50
Jungle map passed for Mi-8
Jungle map passed for Mi-24
Jungle map passed for Mi-28
Jungle map passed for Ka-50