Construction of the Kallang Airport began in 1931 with 300 acres of mangrove swampland being reclaimed. It resulted in the displacement of a large Malay community to the area around Jalan Eunos. Three Hawker Osprey aircraft first touched down in the Kallang Airport around two years before its official opening, on 21 November 1935. During World War II, the Kallang Airport was the only operational airfield in Singapore capable of supporting Allied campaigns against the Japanese forces. It was during the Japanese occupation period that the airport's grass landing zone was upgraded into a concrete runway and extended to 5500 feet. As early as 1950, plans were made to build a new airport at Paya Lebar (the current Paya Lebar Air Base) as the Kallang Airport was unable to cope with the increase in air traffic despite being expanded. The Kallang Airport finally closed in 1955.