Here is the full list of all 50 Heliborne achievements.
Research your first helicopter
Deploy all soldiers from UH-1D during a landing
Lose a night map battle
Have teammates destroy 50 targets with your mortars during single match
Earn awards: "Manpad hunter", "RPG hunter" and "Mortar hunter"
Earn "Mortar hunter" award
Earn "Manpad hunter" award
Earn "Air combat master 1st class" award
Earn "Sniper" award 50 times
Research all 1st and 2nd generation US helicopters
Fully research all variants of 1st and 2nd generation US helicopters
Research all 1st and 2nd generation Soviet helicopters
Completely research all USSR helicopters of all generations
Fully research all variants of 1st and 2nd generation USA helicopters
Completely research all Mi-24 helicopters and their variants
Completely research all AH-1 helicopters and their variants
Fully research all 4th generation Russian helicopters and their variants
Deploy all troops from a Yak-24 during a single sortie
Deploy all soldiers from ACH-47 during one sortie
Deploy all troops from an HH-53 during a single sortie
Earn all game awards at least one time each
Have your UH-60A shot down while playing the Afghanistan, Khost province map
Get grounded having all 3 helicopters in your squadron under repair
Research all variants of the KA-60 helicopter
Win a battle with a custom squadron consisting of only Ka-50 and Ka-52
Win a battle with a custom squadron consisting of only AH-64A and AH-64D
Win a battle with a custom squadron consisting of only Mi-28 and Mi-28N
Win a battle with a custom squadron consisting of only AH-64D and OH-58D
Win a battle with a custom squadron consisting of only Mi-8 variants
Win a battle with a three helicopter squadron customized from the OH line: OH-6, MH-6, MD-500, AH-6
Win a night map battle using custom squadron with only KA-50
Win a battle with a custom squadron consisting only of three Kamov line helicopters with coaxial rotors
Win a night map battle
Win a Co-Op battle
Win a solo Co-Op battle on Hard difficulty
Win a Co-Op battle on 4th generation map set to Very Hard difficulty
Shoot an enemy helicopter down using Ka-226
Shoot an enemy helicopter down using MH-6
Destroy 50 enemy vehicles during one battle
Shoot an AH-64A down using Mi-2
Win a battle using a custom squadron consisting of only recon helicopters
Shoot an enemy down using Mi-1
Shoot an enemy down using H-21
Pick up at least one previously deployed trooper
Bring back and turn in for repairs helicopter with at least 3 destroyed modules
Earn a post-battle cosmetic item reward
Shoot an enemy down using door gunners of the H-34
Deploy 8 MANPADs within 70 meter radius
During a single sortie, exhaust all ammunition of an attack helicopter
Avoid a MANPAD launch or an air-to-air missile