London Stansted Airport (STN) is a 24-hour operation, but it does not "fly all night" in the way many people assume. While the terminal building remains open 24/7—allowing passengers to check in or wait for early morning departures—the airport is subject to strict night flight restrictions enforced by the UK government to minimize noise pollution for local communities. Between the hours of 11:30 PM and 6:00 AM, the number of take-offs and landings is strictly capped. Most of the flights you see during these "night quota" hours are cargo planes (Stansted is a major hub for FedEx and UPS) or delayed commercial flights. Most low-cost carriers like Ryanair and Jet2 schedule their first departures for 6:00 AM and their last arrivals for before midnight. If you are a passenger with a 6:00 AM flight, it is common to arrive at the airport at 3:00 AM; while the security gates will be open and the terminal will be buzzing, you will likely not see many passenger planes actually moving on the runway until the morning curfew lifts.