This photograph of the Istana Besar (official residence of the Sultan of Johor) at Johor Bahru comes from the album of an RAF pilot who served in Singapore, Ceylon and the Pacific between 1938 and 1939.Most of the RAF pilots who served in Singapore during the 1930s were stationed at Seletar Airbase in the northeastern part of the island. Built on a 600-acre site formerly belonging to Singapore United Rubber Plantations, the airbase was operational by 1928 and officially became an RAF station in 1930. The airbase also served as a civilian airport until 1937, when the Kallang Airport was opened to handle commercial flights. Seletar Airbase was designed to handle both conventional aircraft as well as seaplanes such as the Short Singapore III and Short Sunderland flying boats. The first batch of Singapore IIIs departed from Pembroke Dock in the United Kingdom for Seletar in January 1935 to re-equip Number 205 Squadron. The first of the new Sunderlands arrived in Seletar from Pembroke Dock in June 1938 for use by Number 230 Squadron.