Although I didnt have machines in mind and was talking about more animals that can kill you from the sky like demons in the metro series I can except vertibirds though not to often as that can get annoying.

4-5 is an threat to you if they consider you an large enough price to get at any cost.

They would be reserved for emergencies as the one you created.

No not saying it would be as common as dragon in skyrim, however it would be an serious challenge.

You're clearly not reading my comments as closely as you should. I didn't say those 4-5 Vertibirds were the only ones the NCR has. What I said was those 4-5 Vertibirds out of however many they captured at Navarro, meaning they obviously captured more than just 4-5, were all they apparently can afford to field. I understood your comment, you didn't understand mine.

And first, where does it say that the Vertibirds in F3, were produced by the Enclave at Raven Rock, and not just the ones they used to get there? Secondly, you gave an excellent example of one of the Bethesda moment I was talking about in the first place. Why would the Enclave, who is smaller than the NCR, field so many of their precious Vertibirds, when the NCR as big as it is, only fields 4-5 as we've seen? It makes no sense at all, for a small group to put one of their most vital assets out on the frontline like that, in such great numbers, only to be destroyed. If a major power like the NCR, can't field a threatening force of Vertibirds, then neither could the Enclave or Institute, or whoever it is that is flying around in them. It makes no sense.

If you're walking around in F4, and Vertibirds are a flying enemy of the Institute, say, and you destroy 15 or so, then their stock of Vertibirds should be greatly reduced. So much so, you either very, very rarely see them, or not at all because they know they'll only be destroyed. It makes no sense at all to have destroyed 30 in the game, and then destroyed another 30 and another 30.

4-5 Vertibirds going up against one or two people, sure, would be a threat. But an army the size of Caesar's Legion in the Mojave? No, I don't think so. They would have to operated as reserve forces, for emergencies. Which would make sense, and if Vertibirds are like that in F4, great, because it logistically makes sense that a force isn't putting out their entire stock of Vertibirds for you to shoot down, and only using them in times that are emergencies. They could appear like the military did in older GTA's, where your troublemaking becomes so great, a couple Vertibirds come out.

I like the flying enemies in The Witcher 3, harpies and griffons that I've seen so far. They swoop you until you hit them with a crossbow, then recover after a short while if you don't kill them and start swooping again. The dragons in DA: Inquisition were pretty good too but they seemed more scripted than dynamic.

Maybe they could have Vertibirds that act similar to the Buzzards in Borderlands and maybe bird like creatures that act like the Rakk.

OHHHH YA!

I get a JETPACK!

With the help of a fatman anything can fly