I have a 120' tall white oak about 40" diameter at base. Starting below the first large limb about 50' up a vertical crack runs up the center of the main trunk of the tree for 10' going well past the large limb. The crack is about 6" wide and you can see completely through to the other side. The crack tapers at both ends but looks likely to grow at each end. If a tree climber has experience with removing a tree like this advice is appreciated. Tree must come down in chunks. Bucket truck is not an option. Climbing nearby trees is not an option. My sense is to first lighten the load/ remove the previously mentioned large limb that is adjacent to the crack and which obviously caused the crack. I am really not sure about cutting the trunk above and below the split. We are dealing with a big oak here. Thanks in advance.