I have heard this possible but has anyone actually done it?

not to my knowledge.

Nope...

I've seen pear on loquat, here in Florida. That seems to work well. I've not personally seen apple on pear, but the literature indicates that the apple variety 'Winter Banana' can be used as an interstock to put other apples on pear roots.

Your question reminded my of a posting from JoeReal. Look at the 4th entry in the thread.

link

Barbara

Winter banana apple is the trick. Another possible interstems are quinces. You can accommodate many pome species together in one tree. To say that there is no such thing as apples on a pear tree or vice versa is not knowing how to use the search function of this forum. I have recommended winter banana apple as an excellent intergraft. I have honeycrsip, bartlett, moonglow, quinces, hawthorn, loquats and sever other asian and european pears and numerous apples on just one tree that I lost count. You may think i am boasting but it doesnt gain me a penny and in fact cost me time for posting that it is possible and have done it several times over.

Joe, there is certainly no intent on my part not to give credit where credit is due! Glad to see that you posted that info here earlier. But I was not aware of that, and had not seen your posts. Rather, I had seen the info in published propagation literature. But thanks for having put it here earlier.
Malcolm

Quote from Joe:
"I have recommended winter banana apple as an excellent intergraft"
Excuse my ignorance, but I'm not sure what "intergraft" means.
I have a seven in one apple tree (don't know what the rootstock is) and one of the grafts is a winter banana that I got from Dauben (Phillip). Another is Honey Crisp (from Joe... thanks). So, does this mean that I can graft a pear onto W Banana & it will take before a pear grafted to H Crisp?
How cool to have pears & apples on same tree!!

I got banana flower apple scion wood at an exchange last year. I bark grafted it on my apple tree. It took and grew about two feet. This year I bark grafted an asian pear onto the banana flower and it took and grew leaves. It is small but has buds. I learned about this from Joe Real.

Helix

I'm growing several apple trees with winter banana scions from Joe Real with the intent of using it as an interstock. Question I have is how are they as an apple? In searching online quite a few people think they taste pretty good. I wonder what the chill hour requirements are for them.

Phillip