It a pleasure reading the comments, please consider my further thoughts below.
I would say this is really just how the game is coded to handle the situation. Helos are designed to fly at any altitude within the limits of their design. You don't know exactly whether or not an opponent has what kind of AD or where the AD is located. It would be nice to have sensors that detect radar emissions, but maybe that is for a later version. So for now, at some point you have to evaluate the risks vs what you seek to gain. High altitude provides good FOV, so there is value in the information that can be gained. So some may accept that risk under certain conditions. The concept of operation I would like to propose (never flown a helo)
a) Copter goes up to look
b) multiple missiles launched
c) helo takes evasive action
c1) evasive action at high altitude, doesn't make much sense since helo can not out fly missile.
c2) launch chaff and continue to fly at high alt., doesn't make much sense since other SAMs will detect continue motion and fire more SAMS
c3) evade to break missile lock by dropping altitude to ground clutter (I am guess that this is a tactic)
c4) evade to break missile lock by firing chaff and dropping altitude to ground.
d) resolve missile attack (concurrent with c)
d1) at least one missile hit - end of story
d2) all missile miss, helo evades
e) chagne state of helo to evade state.
Since the helo does not move far compared to the flight of the missile, might as well resolve all missile fires in the location of the helo spotted, then if the helo survives, it goes to lower atltitude just as ground units will take cover. The helo shouldn't fly around triggering more missile fires, because it has already got the answer it was seeking by going high in the first place. (can I go high to look around without being shot down).
My view of the world, but by no means the only view
