[learn me] arborist sick tree

i have an apple tree in my yard that is 15~20' tall (not sure how old it is) and one of the tallest sections of the tree had all of the leaves turn brown and when I looked at the trunk where those branches come from I notice that it appears burnt and has sap oozing out of it.  (The tree hasn't been involved in any fire and the damage is above my head so probably 7~8' in the air)

is this section of the tree effectively dead?  Is the rest of the tree going to get sick, should I cut this section off the tree?  If so when is the best time to do it (after the leaves fall, before new buds start in the spring, etc.)  Also should I cover the exposed section of the tree after its removed if so with what?  

I'll try to get pictures of the tree after the rain stops...

FWIW, I have worked with arborists for 20+ years, and they always seem to be able to ID the problem as soon as they see it.

Our last issue:

Hey, why is this smaller tree suddenly dying–and quickly?

See these fresh, thin cracks in the trunk? The tree got twisted during a storm, bugs got it in, and they’re killing it. 

Lightning... dead leaves, burned spot,20 feet tall.

Call a local arborist and tell them what you have.  Chances are they can have someone stop by and give you a free appraisal.

Don't most cities/counties have a forester?

If it was a peach tree, I would have said the Lesser Peachtree Borer.