Video footage filmed by a traveler waiting in the terminal showed a female member of the crew climing onto the wing and "posing like a Disney princess" before waving at a male attendant who stepped out of the emergency exit and onto the wing, the New York Post reported.
Both were filmed posing for photos, and another male flight crew member then appeared on the wing and made "body building" poses.
The video filmed on Aug. 16 quickly went viral on social media, garnering millions of views.
Swiss International Air Lines issued a statement last week criticizing the actions of the crew members, stating that their behavior would not be tolerated.
The airline said it would take disciplinary action and conduct an internal investigation.
The incident took place at Buenos Aires Ezeiza International Airport in Argentina before the aircraft took off for Zurich, Switzerland.
A Boeing 777 wing is around five meters from the ground and can be covered with ice even after having landed in hot climates, due to negative temperatures at high altitudes.