The Coast Guard acquired a Lockheed Model 18 (R5O-1), Lockheed registration number 2008, and it was delivered and accepted on 14 May 1940. It was used as an executive transport aircraft.
The Coast Guard acquired four R5O-4 aircraft in late 1942. These were also executive transports with seating for four to seven passengers. The service acquired three R5O-5 transports later that same year as well. These were the standard transport model with seating for twelve to fourteen passengers. One of the R5O-4 aircraft, service number 12453, served as the commandant’s executive transport.
These aircraft were used primarily for administrative flights and were based at New York and Elizabeth City, North Carolina before the Coast Guard air station was established at Washington National Airport.