Blows bloons away from the Heli.
~ Official Bloons TD 5 Mobile description.

Downdraft is the third upgrade of the second path for the Heli Pilot. It is unclear when it says "Blows bloons away from the heli", because it actually means when the Heli Pilot flies near bloons with this upgrade, it will occasionally blow some of them back to the start of the track (Not in all directions). This is similar to the Monkey Apprentice's upgrades Summon Whirlwind and Tempest Tornado. It is also similar to the Ninja Monkey's Distraction upgrade. It costs $2125 on Easy, $2500 on Medium, $2700 on Hard, and $3000 on Impoppable. When the Heli is placed strategically with this upgrade, it can be useful to use for stalling. This particular upgrade can be useful if you are trying to survive crowds of bloons with the minimal towers. When several heli's have this upgrade, almost no bloons can pass through. MOAB-class Bloons are not affected by this upgrade.