Hello POA,
I am not a pilot, but I stumbled upon Henning on Reddit some months ago and found him to be such an interesting/sometimes disturbing character that I ended up following him around for a bit.
He mentioned sometime last Fall that he was looking to "be gone" (or similar verbiage) by Halloween, 2023. Looks like he held on a few months longer.
I realized this morning that he hadn't posted in a month or so, so I took to Google to find answers and sure enough, found his obit and other Facebook posts.
Being a new account, I can't post links. But his username on Reddit was "Wise_Investment_9089". reddit/u/wise_investment_9089 should get you there.
Not sure if this is meaningful or helpful to anybody but he was interesting enough to fascinate me for a while. His posts/comments on Reddit are definitely indicative of his mental state.
My condolences to anyone who knew him personally.