I don't know but while I was "testing" and "calculating" I somehow went right through it and been able to hop in and out consistently.

Odd. Does this happen consistently, and only when the turbine is assembled? I'm probably returning the wrong AABB for collision so that the rotor doesn't disappear when the bearing is offscreen.

When I say "assembled", I mean "the textures have snapped together and the machine appears finished". It activates an alternate rendering mode for the rotor bearings which requires a different bounding box.

Does this happen when the turbine is inactive, active or both?

This only happens with reactors that have a really big height...(This statement is wrong)
so yeah only if assembled or the controller has information of it being assembled?

That was more of wondering of it than a question for you... I don't make sense to many :P

Anyways, I made the smallest turbine(7x4x7,LxHxW) and just turning it on can allow you to go through it so I guess not the worlds biggest deal... unless you made your flooring out of the turbine.

Can confirm that this only happens with an assembled turbine.

Thanks for the confirmation!
Sadly, it is not needed as the author has acknowledged it as a bug.

possibly related to #411

That bug is possibly due to how the author made the player interact with the blocks...
I'm guessing he's not checking of the player is in the block space.

Looks like a bounding-box problem.

Fixed by 0194855, will be out in 0.4.2A.