High Quality Content by WIKIPEDIA articles! The Henschel Hs 129 was a World War II ground-attack aircraft fielded by the German Luftwaffe. Its nickname, the Panzerknacker (tank cracker), is a deliberate pun—in German, it also means "safe cracker". In combat service the Hs 129 lacked a sufficient chance to prove itself; the aircraft was produced in relatively small numbers and deployed during a time when the Luftwaffe was unable to protect them from attack.