The airport began as a US military airstrip in 1942 during World War II. The following year, the first commercial flight landed on 3 December 1943. The then future Queen Juliana visited the island using the airport in 1944. Eventually, the airport was named after her. In 1964 the airport was remodeled and relocated, with a new terminal building and control tower. The facilities were upgraded in 1985 and 2001. Because of increased passenger traffic and the expected growth of passenger traffic in the near future, Princess Juliana International Airport is being heavily modernized following a three-phased masterplan, commissioned in 1997. Phase I was a short-term program to upgrade existing facilities and improve the level of service at various points. This included widening, strengthening and renovating the runway, increasing the bearing capacity of the taxiways, construction of a new apron and an upgrade of the (old) terminal. Phase I was completed in 2001. Phase II included the construction of a radar facility and a new air traffic control tower, the construction of a new and more modern, 27,000 square metres (290,000 sq ft), terminal, capable of handling 2.5 million passengers per year, and the construction of a Runway End Safety Area (RESA) of 150 metres (490 ft), including a 60 metres (200 ft) overrun, on both ends of its runway, to comply with ICAO rules. The new air traffic control tower and the radar station commenced operations on 29 March 2004, while the new terminal opened in late October 2006. The terminal has 4 jetways for large aircraft like 747s. If traffic develops as forecast, Phase III of the masterplan will be executed, consisting of an extension of the new terminal building and the construction of a full parallel taxiway system. In 1994, the Kingdom of the Netherlands and France signed the Franco-Dutch treaty on Saint Martin border controls, which allows for joint Franco-Dutch border controls on so-called "risk flights", requiring arriving passengers to have valid travel papers for both sides of the island. After some delay, the treaty was ratified in November 2006 in the Netherlands, and subsequently entered into force on 1 August 2007. Implementation has been delayed for several years by the government of Sint Maarten. In July 2016, KLM announced that, starting in October, it would serve the airport with direct flights from Amsterdam instead of the triangle route via Curaçao. The previous triangle route used a Boeing 747. The new direct route would use an Airbus A330. This change ended the airport's last regularly scheduled Boeing 747 service. The 747 made its last appearance at the airport on 28 October 2016. Maho Beach was almost completely covered with tourists and plane-spotters who came to witness the last landing and departure of the aircraft. In September 2017, the 747 did make a brief comeback in the aftermath of Hurricane Irma, operating some relief flights. At the same time KLM announced the return of the triangle route via Curaçao, this time however operated by an Airbus A330. In September 2018, KLM officials confirmed that they hoped to resume direct flights between Amsterdam and St. Maarten by November 2019. On 6 September 2017, the airport suffered significant damage when Hurricane Irma struck the island as a Category 5 hurricane. Video from a Dutch military helicopter showed the roof had been blown off the terminal, the jetways were damaged, and there was a significant amount of sand (blown through the fences from Simpson Bay Beach) and flooding on the runway. The airport reopened on 10 October 2017 using temporary facilities while repair work commenced. Pavilions were in use during reconstruction of the main terminal. In December 2018, temporary arrival and departure facilities opened within the first level of the terminal building. The entire upper floor of the terminal and the four jet-bridges were out of commission until November 2023.