Interestingly enough, even though every single 68W and 18D I've ever met have always been armed with a rifle and basic ammo load, and have been expected to engage the enemy should they be able to do so....Army Medevac helicopters, the DUSTOFFs, are not armed, something somewhat related to the Laws of Armed Conflict and that they have Red Crosses on them. That means that if a Soldier is critically wounded, but the enemy is still in the area, the DUSTOFF has to wait for an armed escort (usually an AH-64). There's more missions than helicopters, there's not always an Apache on standby ready to roll with the Medevac....so they have to sit and wait if need be. There are those who believe this has led to WIAs turning into KIAs.....
Now the Air Force Pararescue (PJs) helicopters, the PEDROs, do NOT have Red Crosses on them (despite being primarily Medevac birds for the Pararescue Jumpers).....and thus they are armed, often not just with the door guns, but often times an M2 .50 in the rear compartment as well....they do not have to wait on an Apache escort and can jump straight into a potentially hot LZ to evacuate the wounded while still defending themselves
Hmm...actually, I wasn't thinking it when I started typing, but yeah, that little comparison between the Dustoffs and the Pedro's is very relevant to the conversation IMO...