I have come across a glitch where a NCR Ranger keeps falling from the sky no matter how many times I kill him. Has anyone come across this and are there any fixes?

Never.

Is it a ranger from the NCR radio?

NCR Radio?

Ah excellent, I see those new jet packs we've been working on must be coming along nicely. Now if we could just work on NOT getting killed everytime we land we'd really be getting somewhere.....

yes, if you have enough likeability from ncr you'll get your hands on a radio to call back-up ncr tropps while in ncr covered lands

1.) I've never seen anything like this. Your save might be corrupt.
2.) Unless your on PC there's probably nothing you can do about it. Though that's not so bad, because that's a pretty funny bug.

If you're on PC, you might be able to fix it by deleting him form existence with a console command or downloading a mod on the nexus.

I had a glitch in FO3 where Tenpenny would randomly spawn in the Mall and start pwning Super Mutants.

Just sayin'.

But no, I haven't seen this glitch.

Just grab his armour and leave the area.