[Imp]

Not used helos for a while but just a couple of questions & observations.

Not disputing armor rating vs small arms fire may need tweaking.
Some do stand a pretty good chance of coming off unscathed by point blank small arms fire as in run up to a hidden squad.

What is taking them down I am guessing APC mounted weapons if 7.62mm so lots of fire at 2-3% hit chance?
Really asking dedicated AA with a hit chance at least in double figures or the above.

I am no pilot but a couple of thoughts on behaviour upon receiving anything much more than rifle fire.
Unless I am extremely experienced I would guess receiving fire from any automatic weapon like a MG would have me running for cover. Good enough to decide sounds like being peppered by a LMG not a 0.5cal or autocannon so we will ignore it briefly. I still would not proceed to stay in its sights for long just in case it gets lucky.
Don't want to test the autogiro feature & my superior would be pissed at my ineptness for wrecking a multimillion dollar machine.

Dion
They are very powerful on maps with cover but they are expensive so if you take fire about the only time you don't take cover is a brief dash to a safer local while receiving fire at 1-2% hit chance.
Don't under any circumstances charge with them, by all ,means especially if TI equipped use them as scouts but sensibly as you would a scout vehicle. They are worth their weight in gold for this ability & the capability to quickly plug gaps. Their other role is to take out a target in a position that it is hard to mount an attack on.

Avoidance is the key as a rule repeated fire will make them run however in most cases popping up or exposing to take a shot & receiving a few shots they stay. Now its threat assessment time depending on what fired do you take the shot or duck so as not to draw more which might force you to do so.
Maybe with low experience morale sides (under 70) they react differently.
Same as ground units never move more than a hex or 2 if you are going to fire.
Unless you know its safe move them a few hexes at a time, they are not hovering once speed is up.

Making life easy for helos
Buy a flight of SEAD aircraft & at least some CM arty
Use them to take out hard target AAA & other arty or ground forces to take out or suppress other AAA assets.
Also makes sense to have scout helos ratio anything from 2-1 to 1-2 is common that way if one receives fire there is a chance someone will see it.
Work with your ground forces most of the time scouting & taking out their big threats while they deal with yours.
Don't be impatient if you can take the enemy out with ground units do so save the attack helo & its limited ammo for the tricky situations or forcing a break through.