The hull is constructed of duralumin over a wooden frame, and the fuselage was built on top of the hull. The OA-lA is powered by a 420-horsepower, water-cooled Liberty V-12 engine that is mounted inverted.
The historic Pan-American Goodwill Flight of 1926 and 1927 through Mexico and Central and South America was intended to improve relations with Latin American countries, to encourage commercial aviation, and to provide valuable training for Air Corps personnel. The flight was made by ten pilots in five Loening OA-1A amphibian aircraft. To stimulate public interest, each airplane was named after a major U.S. city-the New York, the San Antonio, the San Francisco, the Detroit, and the St. Louis.
The 35,200 km (22,000 mi) flight began on December 21, 1926, from San Antonio, Texas. The journey took 59 flying days, interspersed with 74 days for scheduled maintenance and diplomatic meetings and ceremonies. The flight concluded at Bolling Field in Washington, D.C., on May 2, 1927. Within three weeks, however, the impressive achievement was eclipsed by Lindbergh's solo trans-Atlantic flight in the Spirit of St. Louis.
Loening OA-1A San Francisco
Engine: Liberty V-12, 313 kw (420 horsepower)
Wingspan: 13.9 m (45 ft 7 in)
Length: 10.7 m (35 ft 1 in)
Height: 3.5 m (11 ft 6 in)