Special attachment for back-filling deep holes?

Got a job coming up that requires us to backfill 3' to 6' diameter holes, 50' deep, with sand.

Typically I would just use a loader bucket, scoop, dump and push the sand into the hole.
But considering we will be doing several holes a day, with LARGE quantities of sand, I want to optimize the process.

Is there a good loader bucket attachment with some sort of funnel that I can place directly over the hole so there is no spillage on the sides of the hole?

Is there a possible better piece...

Special attachment for back-filling deep holes?

Special attachment for back-filling deep holes?