Helicopter assaults

[KG_RangerBooBoo]

Anyone care to expound on the best way to pull off helicopter assaults? Do you carry troops in close and risk the choppers or do you set down a safe distance away and make the grunts walk in the rest of the way. I've been trying to set down fairly close but it's costing my choppers so I'm thinking I should be doing the opposite but then I'm losing the mobility advantage of the birds. Along that note I wouldn't mind playing one of the MW, Falklands, or Vietnam scenarios as the bad guys so I can see how someone else does it.