Because arming them doesn't make them harder to shoot down. The threat to the helicopter isn't really the small-arms fire, although IRL it is dangerous to them. In-game, the biggest threat to helicopters from the ground is generally MANPAD missiles, Heavy Anti-Tank weapons, 12.7 and 14.5mm machine guns and Light Anti-Tank weapons in that order.Maverick wrote:If they're so easy to shoot down, then why they have no guns?(sides from squadron mates)
With the possible exception of the HMGs, by the time the helicopter is aware of the threat (either because there's a streak of smoke charging towards the bird or a threat tone sounding), there's generally very little any door gunner can do to neutralise the threat. Even in the case of heavy automatic fire, the chance that door gunners are able to locate and then supress and/or kill the threat before the bird has suffered pretty major damage is pretty slim.
All that door guns do is allow small-arms fire to be supressed at an unexpectedly hot EZ/LZ, and even then they'll probably be insufficient to stop major damage to the passengers or crew, even though the bird itself is likely to survive.
In short:
Transport helicopters don't survive because they've got door gunners on them. They survive because they stay away from enemy units, don't attract attention to themselves and get the hell out of the area once attention is focused on them.
Jaymz
