My mother in law came quiet recently by the same air lines, she did not take transit visa. It is not required as long as ONE has valid USA visa. She has 1 year Multiple entry visa.
Same should hold good with AP, atleast in theory.
But in practice, not sure if German immigratin knows much about AP.
Send mail to German consulate in USA about your situation.
They respond very quick for the email.
Give a shot.