Here is what I do.

Get about 5 foot of hard PVC pipe, 2 90 degree PVC elbows, a PVC tee, 1/2 foam pipe insulation and a PVC end cap PVC glue, plus a 6 to 10 inch garden spike. All about 1/2 inch in diameter. Oh forgot about a length of 1/2 inch diameter dowel rod.

Cut 2 10 inch pieces of pipe
Cut 1 8 inch piece of pipe
Cut 1 2 inch piece of pipe

Take the tee and grind out the ridge on the inside of it so the 8 inch piece will slide all the way through. Once I have the 8 inch piece centered in the tee, I drill through the tee and the 8 inch piece at the top of the tee and insert a sheetmetal screw. I then back out the screw and elongate the hole, in the tee only, about 2 to 3 inches and reinsert the sheetmetal screw, epoxying it in.

Now I take the end cap and drill a hole in the center of it the same diameter as the garden spike and shove the spike into it and epoxy the heck out of it. I then shove the dowel rod into the pipe and epoxy it in there. I then glue the other end of the 2 inch pipe into the tee at the bottom.

Glue each 90 degree elbow to the 8 inch pipe on each side of the tee and glue the 10 inch uprights to each elbow. I cover the 10 inch uprights with 1/2 thick pipe foam to help protect the plane.

You shove the whole thing into the ground, the slot you cut out allows it to pivot, so you face the slot towards where the tail of the plane is going to go and let the uprights fall to the ground. Now set your plane on top of the tee so that the tail clears the uprights that are now laying down and rotate the uprights to the upright position and push the plane against them. The plane will hold them up and once you start the engine and due the engine checks, the pressure on the uprights will keep them against the tail. Now to release the plane just pull it backwards enough to let the uprights drop.

This sound like allot but I have built several of these in varying sizes for other pilots and it takes all of an half an hour to do. You can use larger or smaller pipe sizes and can either shorten or lengthen the uprights and the piece that goes through the tee depending on your needs.

I will post pics later tonight and if anyone wants I will even make it for you for a very small fee plus shipping. PM me if you want me to make one for you.