I've been having this issue for some time now, and wonder if there is a way to fix it.

It happens to BoS, Outcast, and Enclave NPCs, and on all the variants of power armor.

The glowing purple power armor is noticeable both while the NPC is alive and dead, but the flickering usually only begins after the NPC is killed.

I will try to get some screen shots of the "glowing purple" effect, but usually, when I'm engaging power armor clad foes, I'm using hit and run tactics...

Their glowing purple? Do you have any mods which changed the textures of Power armor, or did you uninstall any mods that made such a change? Sounds like a missing texture to me.

I don't have any mods that modify the power armor textures... that I know of.

http://www.fallout3nexus.com/imageshare/images/170821-1278709588.jpg
Notice that only parts of the armor are glowing....

Those armor parts do have texture, otherwise they would be solid purple, i've never seen anything like that. Closest thing would be corpses that turn green with Mart's Monster Mod for Oblivion if it's not properly installed.

I've looked at "Data\Meshes\Armor\teslapowerarmor\outfit.nif" in NIFSkope, and the textures show up normally. (This confirms the fact that the power armor is modified from vanilla, seeing as it is a loose file in the Data folder.)

I sort of thought that this wasn't a missing texture issue, since the glowing purple isn't solid like I thought it should be.

I'll start paying closer attention to what parts of the power armor is glowing on each variant of the suits. Maybe I'll be able to isolate it to specific parts on each particular type of power armor.

Also, this doesn't address the flickering that happens when a NPC in power armor goes down.

I'm leaning toward the notion that this may be a buggered flag somewhere in the BSShaderProperty block, or something set screwy in the NiMaterialProperty block. But the only thing is, if that were the case, I wouldn't be the only person seeing these artifacts.

Thanks for the replies, and I'm still open to suggestions as to what could be causing this...