How small of a space can a Northern Goshawk fly through?

How small of a space can you fly through? This Northern Goshawk shows off its unique skills with a few lab tests filmed in ultra slooow-motion. More from AllAboutBirds.org:

The Northern Goshawk is the bigger, fiercer, wilder relative of the Sharp-shinned and Cooper’s Hawks that prowl suburbs and backyards. It’s an accipiter—a type of hawk with short, broad wings and a long rudderlike tail that give it superb aerial agility…

Northern Goshawks alternate short flights with brief stops at elevated perches as they search for birds and small mammals in the forest, and cruise along forest edges or over shrub habitat seeking prey. They glide quickly and silently, striking unwary quarry feet first. If detected, these reckless hunters fly at high speeds in pursuit of fleeing prey, maneuvering through the forest using their long tail as a rudder, crashing through brush and even chasing a potential meal into the water if necessary.

(Updated video link.)