Lets take the fact that you have an engineering degree out of mind because it means ziltch in the world of education. I'd be interested to know how old you are. Anyway, you probably have a bunch of science requirements seeing as you majored in engineering, but you still have to obtain the education credits and that takes a lot of time in some states. So, as they say, I wouldn't quit your day job just yet.
Also, you will have to wait along time to become head coach and as an assistant on the high school level you don't really design training plans don't get too excited.
Summers off. Meh, not really a good enough reason to become a teacher yet it is the main reason many people do. But its overrated. What are you gonna do for 10 weeks knob off and run. Its actually a reason I don't want to be in education. And please understand that you start off at the lowest base salary know matter what in education and their is no expedient way to make more.