Don't be alarmed. Over 80% of public U.S. schools are labeled as failing. This label does not adequately reflect what is going on in schools and the quality of the school, its staff, or the education students receive. I would disregard it entirely and decide for myself. Visit the school and the staff. Talk to neighbors with kids who attend. Get involved.
Private and charter schools may or may not be better. Private and charter schools pay their teachers an appallingly low salary for the amount of education and experience teachers have. Unless they don't need the money, private and charter school teachers often try year after year to get a better paying job, so turn-over may be high and job satisfaction low.
As a public school teacher, I spend $2000 of my own money every year for my class to enrich the learning experiences for my students. I provide everything from basic school supplies my students' parents won't provide, consumables for art, math, and science projects, field trip admission, subscriptions for educational materials, and technology, including a laptop, projector, and wireless internet. It's not right, but that's the way it is. At least I can afford to do this.
My daughter is a teacher in a charter school, and even with a master's degree, is not paid enough to live on, let alone buy all these things for her class. She does the best she can with what she has.
Most teachers in all schools are working so very hard to give their students a good education, and the government's assessment of the quality of education is not a good indication of the gains each student is making. Please check for yourself and find the school that is best for your son and the way you want him to be taught. There are many differences. Also, find out if special area subjects, like physical education, are taught by certified, highly qualified teachers and if special services are provided, such as reading intervention, speech therapy, and special education. Does the school have air conditioning? Good luck!