On 27 July 1934, a Swissair Curtiss AT-32C Condor II passenger aircraft crashed near Tuttlingen, Germany, while flying through a thunderstorm.

[2] The aircraft involved in the accident, registered CH-170, was a Curtiss AT-32C Condor II, a variant of the standard T-32 developed specifically for Swiss flag carrier Swissair, which was its only operator.

[3] The aircraft's flight attendant, Nelly Diener, also known as the Engel der Lüfte ("Angel of the Skies"), was Europe's first air stewardess.

Shortly after crossing the Swiss-German border, the aircraft, cruising at an altitude around 3,000 m (9,800 ft), encountered a thunderstorm, and while flying through it, experienced turbulence.

[3][5][6] Investigators found that oscillations in the wing had caused a stress fracture, the severity of which was exacerbated by the violent weather conditions in which the aircraft was flying.