Knowing that the airport in New Orleans is an international airport, I had already suspected that the longest flight out of our state would likely originate from there, and I was correct. According to my search, the longest flight you can take out of Louisiana is for 8 hours and 50 minutes. Longest Flights Out of New OrleansAs for the second-longest flight out of Louis Armstrong International Airport, it's to Seattle-Tacoma, and that trip is just over 1,800 miles. Coming in third, for the longest direct flight from New Orleans is the flight to San Fransico, which is approximately 1,660 miles. For fun, I looked up the shortest flight out of the New Orleans airport, and that's a flight to Houston, which has an average of nine flights per day.