F 2 Hägernäs , actually F 2 or Kungl Roslagens flygflottilj , (flying corps), was a former naval aviation flotilla within the Swedish Air Force, located in Hägernäs in Täby outside Stockholm.

F 2 was the only one of the air force flotillas that lacked a runway because it was a seaplane flotilla. The planes were taxied straight out into the sea from the hangars. The unit's area also included Tornön in the bay outside the corps' area. Tornön was used for military training activities, including training in explosives.
 

During the 1960s and 1970s, the unit mainly consisted of ground training. KAS/M, which was the Swedish Air Force's Cadet and Aspirant School (Marklinjen), as well as corporal and lieutenant school for future non-commissioned officers in STRIL service within the Swedish Air Force. The unit also had STRILS, which was the Swedish Air Force's combat command and air surveillance school.

Between 1948 and 1958, the Air Force initially had three Tp 47 Canso (Catalina) based on the F 2. One of the three Catalinas was shot down by Soviet fighter aircraft while searching for the missing DC-3. The two remaining Catalinas were then rebased to F 8 Barkarby where they served until 1966.

The two Catalinas searched for the DC-3 all night on June 16 without success. Due to wind and current conditions, the search area gradually moved northward, and both planes were almost ten miles north of where the DC-3 was probably when contact was lost. At 04:09, F 2 at Hägernäs received a message from one of the Catalina planes: “Flying attack by two MIG planes.” Two minutes later, a new message came: “We are being fired upon with tracer light, 20 mm. It is hitting the right.” At 04:15, a message came from the other Catalina: “I am being fired upon and hit several times.” By 04:20, the plane had been damaged so badly that it was forced to make an emergency landing. The crew of the West German cargo ship Münsterland, which had witnessed the entire incident, picked up the aircraft’s crew. Everyone survived, but the pilot Carl Olof Arbin and the navigator Ove Engberg were wounded.

F 2 also housed the Swedish Air Force Radar School (FRAS). Personnel were trained there, among other things, in combat command (of air) and air surveillance. This was done with the help of very modern and advanced technical equipment for the time. In the years 1951-61, the Swedish Air Force Weather School was also located at F 2.

Flotilla commanders: A. Örnberg (1926-29), CA F:son Egerstöm (1929-32), SA Flory (1932-34), HG H:son Enell (1934-36), H. Sundin (1936-44), SOH Swenow (1944-48), CR Weidling (Tjf chief 1948-49), KOG Sandberg (1949-57), TP Sjölin (1957-70), A. Persson (Tjf chief 1970-71) KW Normelius (1971-74).