The floor below the intermediate column in the corner is floor 81.For starters the vertical column in the top hole is intact, splitting in half ..minus the width of the column itself leaves a hole substantially less than than 3 feet wide. I think the corner verticals are on alternating floors so I'll need to check for the bottom hole which is much less clean anyway.
PS. Can ya lend Sayit a nickel??
That logically matches with the hole created by engine on the impact side of things as that shows to be in between floor 81 and 82.
Here is a photo of the smoke streamer produced by the engine after leaving the tower.
Oh look! Damage to a building (circled by the red oval) from the engine hitting it.