[1] The F-1 was a biplane flying boat powered by two 160 hp (120 kW) Hall-Scott A-5 liquid-cooled engines with two-bladed tractor propellers fitted between the two wings.

[2] Preliminary design work had been started by Alan Loughead in early 1916, and they began its construction in a rented garage, which soon attracted the attention of 20-year-old John K. "Jack" Northrop.

[2] When the United States entered World War I in 1917, Allan Loughead went to Washington to try to get a Navy contract to build the F-1 in quantity.

Allan Loughead and a crew of three flew it from Santa Barbara to San Diego in April 1918, setting a record of 181 minutes for the 211-mile flight.

The mechanic worked on the engine while the two pilots caught a train back to Yuma to have the broken tailskid repaired.

[2] The brothers sold the F-1 in 1920 to raise capital to develop the S-1 sports biplane; the new owners were to have used it to fly to Catalina Island, but it was abandoned on the beach, and was slowly destroyed by vandalism.