Helicopter damage rebalancing

[sqlfoxhound]

Considering that helicopter hull does not register small arms fire and is the only damage category which, upon reaching 100%, will destroy the heli, it has lead to a situation where currently the only way to kill a heli is to hit the engine block as this will shut down the rotors and essentially make the helicopter crash.

The areas in relation to the whole surface area are not only extremely small, but counterintuitive because they differ between heli types.

In practical terms, this means that in order to shoot a helicopter down, the player has to hit a surface area which can be compared to a human head in case of Huey's top and a marginally larger area at the back/bottom of the LBirds.

Upon attempting to ambush a heli dozens of times, "reviewing" a lot of gameplay footage and having flown for hundreds of hours, mostly in combat, in order to kill a heli, the players are required to execute the perfect ambush situation where a heli is on the ground or has it's engine (or rather the area which registers engine damage) exposed, and even then, the distances at which the helis are usually engaged yet again dictate the players to be required to hit a surface area comparable to a human head.

In order to fix this, I propose the following fix-

Damage to INST, MRT and ATRQ aswell as ENG should all shut down Engine if the damage reaches 90%+.

[EDIT] This might seem like a major change bordering unbalance against helis, but these parts take so little damage in ambushes and fights already. Typirally, in my anecdotal experience, a flyover through a squad ambush at elevation of 200-300m nets me less than a quarter INST damage, no engine damage, maybe 15% tail rotor damage and anywhere from 0 to 100% MRT damage depending on tilt, attitude, speed and the luck of the players on the ground crew. These figures are based on countless flyovers over a squad of 3-4 people using LMGs and MMGs.

Visual TL;DR version http://imgur.com/a/GV5Cx