When else in considered perrmissible to kill another just because you wish too?
I dunno about “else”, but any time another organism is living on my blood oxygen, I feel quite at liberty to get rid of it.
YMMV, and it would be the height of hubris for me to dictate or restrict others’ options in that regard.
If you’re piloting a plane, your passengers are living on your blood oxygen.
If you’re piloting a plane, your passengers are NOT living on your blood oxygen in any meaningful sense.
So who died and left you in charge of ruling on which senses are meaningful? If your* blood oxygen level drops too much they’ll die.
Who died? The fucking pilot.
Like you, I have only ever flown with a flight instructor.
(* You were the pilot, not me. If you make me the pilot the scenario doesn’t work. My passenger isn’t living on my blood oxygen— I’m not a good enough pilot. If my oxygen level drops my passenger will just take over — the only passenger I ever had was my flight instructor.

)
Nobody is living on the the blood of the dead pilot from whom I had to take over, nor is anyone living on mine. There is no parasitic relationship there. To be more precise (as you seem to demand, and I appreciate that) they are not using your blood or other tissues as a transport medium for oxygen, nutrients, hormones, and wastes
Au contraire. That’s exactly what they’re using your blood for. If that stuff doesn’t get transported around your body, they’ll die.
No they won’t. It will have zero direct effect upon them. Impact with the ground might kill them, but in the meanwhile they - or someone else with equal or greater piloting skills than mine - can take a whack a piloting the plane if my blood becomes ineffective at enabling my piloting skilz.
or to otherwise fuel their biological functions. I think you know the qualitative difference, and that makes your response feel somewhat disingenuous
I know the pilot scenario isn’t what you had in mind; I don’t know how you’d go about making your explanation of when you’ll feel at liberty to get rid of an organism more precise; but that’s not important since I know you can if you set your mind to it. What I don’t know that is important is why you think whatever hair-splitting distinction you’ll come up with is morally significant.
Morally? I don’t do “morally”; that is a construct for others to employ in the dubious pursuit of passing judgment upon me.
Why does it make a difference whether the oxygen and nutrients they’re relying on your blood to keep transporting in order to not die are yours or theirs?
I did not design the human reproductive system. Your question goes back to “why” some people demand an anthropoid god.
For at least 5-6 months the fetus can die and the host (mother) can live. Vice versa, not so much.
It was in hope that you’d explain that that I brought up pilots.
You’re welcome.
Why is a post-viability fetus riding in your hypothetical uterus morally different from a born baby riding in a hypothetical plane you’re flying,
It (a baby) has experiences , acquaintances, living memories, and - more germane - is in the memories, hopes and dreams of people other than the former host (mother). That’s one big reason why, in my amoral judgment. (I don’t do “moral”) a fetus is different from a baby.
to make you feel at liberty to get rid of one organism and not the other?
I don’t have any such feeling. (Please don’t further indulge in trying to bolster your arguments by imagining/ assuming my feelings)
I “felt” compelled to help rid my wife of four ectopic implantations. Liberty has little to do with it, other than the fact that the option to save her life was not restricted (at the time) by lack of liberty.
Liberty, in this scenario, is (was) the default state. I oppose the changes to that condition that have occurred since, and “feel” very sorry for women made victims by those changes. Call that morality or immorality - I care very little for those loaded terms.