 Pan Am began transatlantic Constellation flights on January 14, 1946, beating TWA by three weeks.In January 1946 Miami to Buenos Aires took 71 hours 15 minutes in a Pan Am DC-3, but the following summer DC-4s flew Idlewild to Buenos Aires in 38 hr 30 min.In January 1958 Pan Am's DC-7Bs flew New York to Buenos Aires in 25 hours 20 minutes, while the National – Pan Am – Panagra DC-7B via Panama and Lima took 22 hours 45 minutes.