Here's what matters:
* High School Equivalency Diploma: The Air Force accepts GEDs and other high school equivalency diplomas. An alternative school diploma *might* be considered equivalent, but it will need to be verified.
* Accreditation: The alternative school must be properly accredited by a recognized accrediting agency. The Air Force will check this. An unaccredited school's diploma is unlikely to be accepted.
* Coursework: The curriculum should meet minimum standards in core subjects like math, science, English, and social studies. The Air Force will review the transcript to ensure sufficient academic preparation.
In short: You need to contact a Air Force recruiter directly. They'll be able to assess your specific diploma and determine if it meets their requirements for enlistment. Don't assume anything; get official verification.