Assuming tongxian is required, the following result was found.
Beijing Capital International Airport 40°4′20″N 116°35′51″E Beijing Shahezhen Air Base 40°8′57″N 116°19′17″E Beijing Tongxian Air Base 39°48′40″N 116°42′30″E Note that I tend to copy the coordinates off a website which has strange apostrophes and...