Thanks for the reply, but this is NOT a solution. Getting a competent squad together for one challenge is unreasonable.
The fact is this challenge is just pure crap. The IGLA requires 2 hits on attack/trans helis, if you manage to even get 1 hit you still need to find the magic of getting another without the pilot NOT popping the flares early, NOT going under radar, NOT going too far AND having to be locked on like an idiot sitting out in the open with a scope on the aircraft.
If the pilot bails and you get a force bail, you don't even get credit, let alone getting credit for an assisted kill.
The challenge is bad. It's really really bad. Just admit that and remove this stupid challenge or make more fair to just destroy aircraft in general/assist.