After grabbing Paladin Cross at The Citadel, we headed to the Arlington Library. As we round that last curve, a helicopter flies in over the Library. I think, "Wow! This is cool!. I wonder who that is?"

It flies in and lands in the parking lot across the street from the Library. As it leaves, there are 3 Enclave Soldiers left behind. After an intense battle (I was down in health), Cross and I dispose of them. I think I had a sliver of health left. Then... a car in the parking lot explodes. Dead Meat goes flying.

The next time (reloaded), I used the cars to my own advantage! That was cool seeing the Enclave "helo-drop" in like that as a random encounter. I especially welcomed this as I had a near broken Plasma Rifle I was lugging about and all 3 of them had Plasma Rifles in their inventory. I hope to see more of them

Yeah i think there's a few random spots that they show up in on the helicopters. They also have set outpost locations through out the wasteland once you reach that far in the main quest line. makes traveling the capital wasteland that much tougher, and more fun.

I dunno how random they are, after they show up at the Jefferson Memorial during the main quest, I see a vertibird drop off soldiers next to Dukov's Place every time I pass by it. There's another part of DC, I can't remember for the life of me what it's called, but there are two vertibirds that drop off people right near a bunch of super mutants. Makes for a crazy three-way battle.

The capital building, where super mutants and talon company are fighting already. A vetabird always drops in there. I think they drop off a deathclaw too? lol The battle there is insanity. I'll have to go visit when i get that far in the main quest and i think you are right, i was wrong about the random spots. I think they are set locations where the vetabirds show up.

When you come across an Enclave Eyebot in the wastes, shoot it and hang around. If your lucky, someone will come to find out why the transmissions have stopped.

There will also be a drop across the road from Jocko's Pop and Gas. Usually when you exit the building.