Loon I had a 8"-9" maple that exhibited the same problems a couple years back or so. The top finally blew down this spring. With a tree your size, I wouldn't wait.....
Tractor is down the road so had to improvise. Both had a North lean to them so it was pretty anti-climactic. Pretty sure the big girl didn't even budge. Dragged the closest one for the pic as it fell on the other maple.
The ladder way sure aint the way to do it right guys. Nothing happened and they didn't seem too big till they dropped. Now cutting down some good Christmas tree's around the house that didn't make it through last years drought.