Reference for Chullin 113:7

שמוטת גף בעוף טרפה חיישינן שמא ניקבה הריאה

it is permitted; if the femu of an animal was dislodged, it is trefah; if the femur of a bird was dislodged, it is trefah; if the wing of a b was dislodged, it is trefah, for we apprehend that the lung has been pierced.

Jastrow