F 1 Hässlö

F 1 Hässlö, Kungliga Västmanlands Flygflottilj, Royal Västmanland Air Force Wing, or simply "F 1'", is a former Swedish Air Force wing with the main base located at Hässlö Flygplats in Västerås in central Sweden.

History of the airbase
The 1st Flying Corps was set up near Västerås City July 1, 1929 on the grounds of the recently disbanded 18th Infantry Regiment. The airfield at Hässlö was brought in use in 1931. In 1936, the 1st Flying Corps was redesignated F 1 as the 1st Air Wing and received B 3 bombers. These were later supplemented with B 4 dive bombers.

In 1949, F 1 was reorganized as a night fighter wing with 60 surplus J 30 De Havilland Mosquitos from England. They were in turn replaced by 60 J 33 Venoms in 1952. All of the J 30 and J 33 in Sweden were based at F 1.

In 1959, the night fighter squadrons were converted to regular fighter squadrons of J 32B. These were in service until 1968 when they were in turn replaced with J 35F until the decommissioning of the wing in 1983.

Current use
The airfield is known today as Stockholm-Västerås Airport with daily flights to England and charter to Mediterranean destinations.