Why do the apples in my pie fall?

You could always try cooking them first. Apples have a lot of water in them, and shrink when they're cooked.

When i make apple pie, i'll peel core and dice/slice the apples, put them in a pot with cinnamon, nutmeg and a teaspoon of sugar with about 2 tablespoons of water. I stir them the whole time for even cooking (there's usually lots when i start), and cook them until they start getting soft around the edges.

I always think my pies turn out nice, but i guess i've just got my husband and kids to agree with me on that.

If you give it a go, just be sure not to over cook the apples. They could come out slightly sluggish. Over cooked apples turn into a really thick type paste. (i've cooked a pie like this before, it was nice, but needed lots of cream/custard to offset the thickness of the apple)

The crust on your pie forms faster then the apples cook. After slicing your apples Toss all of the apples with 1/4 cup of the sugar, place in a colander set over a large bowl and allow to drain for 1 1/2 hours. This will alow the apples to lose the moisture in them that makes them shrink leaving you with the gap. You can reduce the liquid that drained over medium heat and add it to the pie.

The apples cook down considerably and shrink. The only apples I ever use are granny smith for my pies.

The crust bakes over apples but doesn't 'accommodate' them when they shrink.

My best guess would be that your apples are too big.Try making them into smaller slices. Ethier that or your crust is to thin.

apples shrink when they are cooked you have to really pile them up as high as you can

Do you not use pie funnels in the US?