Seven former B-17F U.S. Army Air Force Flying Fortresses were converted into "Felix" airliners by Swedish aircraft and auto manuifacturer Saab during World War II. The company advertised the conversion program using the biblical quote, "From swords into plowshares," signifying conversion of the former warbirds to peaceful use. Five went to Swedish airlines ABA and SILA (Swedish Intercontinental Airlines), and two were sold to DDL (Danish Airlines). The Felixes served the airlines until 1948, when the last was retired.