was intended as a link in a northern air ferry route known to U.S. planners as the Crimson Route, but it transpired that few aircraft were ferried to Europe through it. Instead, the base earned its keep as an alternate field, a radio and weather reporting station, and as a departure point for search-and-rescue operations elsewhere in Greenland. During the two years Colonel Balchen was in command, he led numerous expeditions throughout the island, primarily in rescue operations for downed aircrew. As a reliever for the Greenland Command headquarters base in Narsarsuaq, Bluie West One, BW-8 was by late 1942 assisted by small fields at Bluie East Two in East Greenland, and Teague Field on the west coast about midways between BW-8 and BW-1. The Danish government briefly controlled the base in 1950, but following a renewed base treaty (also resulting in the construction of Thule Air Base), the United States reopened BW-8 under the name of Sondrestrom Air Base on 27 April 1951. Sondrestrom AB then became instrumental in the airlift to build Thule AB, although it had little function of its own, and rarely had permanently stationed aircraft. However, the base also served to support air refueling tankers, and trans-Atlantic ferry flights for short-ranged jet fighters continued to transit in the post-war period. When the Distant Early Warning Line was constructed in the late 1950s and early 1960s, Sondrestrom AB received a new lease on life. It assisted especially in the building of the four radar stations spanning Greenland (DYE-1 through 4). In the mid-1950s, Scandinavian Airlines System (SAS) began using the base as a refueling station on their then-new "Polar route" between Scandinavia and the United States. In 1956, SAS was operating three round trip flights a week with Douglas DC-6B propliners on a routing of Copenhagen – Sondrestrom – Winnipeg – Los Angeles. In the early 1960's, SAS' new DC-8-33 jets operated a Copenhagen-Sondrestrom-Los Angeles route. This use declined in the mid-1960s, as fan-jet airliners gained greater range. In the 1970s, Boeing 707-320B jetliners operated by Dan-Air between the United Kingdom and Vancouver stopped to refuel. The base also became the hub of Greenland air traffic and was the destination for almost all regular air service from and to Copenhagen. The United States Air Force continued to use the base for occasional traffic, and in particular for the yearly resupply of the DYE stations. It was