What did the Smithsonian give in exchange for its Super Constellation?

The Smithsonian's National Air and Space Museum (NASM) Super Constellation is a C-121C (1049F-55-96) with the former Air Force serial number 54-177, now registered as N1104W. It was one of 33 C-121C delivered to the United States Air Force and the Atlantic Division of the Military Air Transport Service at Charleston Air Force Base (South Carolina). It arrived there in March 1956 and was assigned to the 1608th Air Transport Wing. Its original configuration was as an overseas cargo and passenger transport, with eight crew members and capacity for up to 80 passengers.

It was retired from military service at the end of 1977 and remained stored until 1981. It was meant to join a small fleet of passenger Constellations flying between Los Angeles and Reno (Nevada) under the Classic Air brand, but the company failed to obtain FAA approval and the aircraft remained grounded.

At that time, the NASM was looking for a Super Constellation for its collection. Darryl Greenamyer, who had acquired two of those Constellations, negotiated an exchange with the museum: the C-121C N1104W in exchange for two Grumman HU-16 Albatross. The aircraft is displayed at the Steven F. Udvar-Hazy Center, next to Dulles Airport. The museum considers the Super Constellation and its derivatives to represent, along with the Douglas DC-7, the final step in the development of the longest-range, highest-capacity, and most powerful piston aircraft. The Super Constellation, which first flew in 1950, was built in about 579 units, and the last ones remained in domestic service in the United States until 1980.