Not a glider, but I had a redtail hawk come fly in formation with the Aeronca Champ I was instructing in, he maintained position about 6 feet in front of the right wing as we were rounding out and flaring for a 3 point touch down. Just before we touched down he pulled up like he was going to go over the top of the wing. He missed and hit the leading edge of the wing. He must have hit on one of the ribs as there was no damage to wing, but it did kill the hawk.

Brian
CFIIG/ASEL