[3][4][5][6] The Plymocoupe, classified as a "flying automobile", utilised the engine, dashboard, indicators and hood ornament of the 1935 Plymouth car.

[4][7][8] Based on the Swanson-Fahlin SF-1, Fahlin used a regular six-cylinder in-line Chrysler car engine, adapted to aircraft use, to power the airplane, supported by rubber suspension.

[7] The SF-2 engine was required to pass two series of tests before being granted the ATC (Approved Type Certificate) which would allow it to be used in aircraft flight applications.

At the same time the Bureau of Air Commerce asked Fahlin Aircraft Company in Marshall, MO to manufacture an airplane which would be used to test the certified engine in flight.

On a trip between two cities in the midwest of the United States it took the airplane two and a half hours to cover a distance of 250 mi (400 km; 220 nmi).

However the failure of the SF-2 to win the competition and the death of Fahlin's partner Swanson, from pneumonia, led to the sale of the aircraft to Russel Owen, who was planning a non-stop flight from Anchorage to Seattle.

"[11] The aircraft had the name Se As Ka at the pilot door followed by the description "The Flying Automobile", while the side of the fuselage was inscribed by the message "Seattle-Alaska Last Airmail Frontier Trail Blazed by The Seattle Washingtonians".