In the US Navy designation system, the J was for utility aircraft and the O for Lockheed until 1951, with the V being for Vega. The single JO-1 was an L-12A for the US naval attache in Rio de Janeiro. The first of five JO-2s staff transports was delivered in September 1937, and three went to the Marine Corps. BuNo 1049 served with VMJ-1 at Quantico for use by Headquarters, USMC. It was struck off charge in November 1943. 1050 was also with VMJ-1, but crashed in September 1938. 1051 served at MCAS Ewa near Pearl Harbor in December 1941 and was destroyed in the Japanese attacks.