AP Style holds that “air base” is two separate words.
You should follow the practice of the United States Air Force, which uses “air force base” as part of the proper name for its bases in the United States and “air base” for its installations abroad.
On second reference use, “the Air Force base,” “the air base,” or “the base.”
Do not abbreviate, even in datelines. For example,
- ANDREWS AIR FORCE BASE, Maryland (AP) —