Einar Sem-Jacobsen entered the first flight in a military mission at Elverum 1 September 1912 with Ganger Rolf, one of two Farman Longhorn that initiated the Army Air Forces the same year.
On September 1, 1912, Einar Sem-Jacobsen participated in a military flight at Elverum with Ganger Rolf, who was part of the first pair of Farman Longhorn aircraft to establish the Army Air Forces that same year.