Bad Aibling Station

Bad Aibling Station
Part of National Security Agency (NSA)
Located in Bad Aibling, Bavaria, Germany
Radomes of Bad Aibling Station
Bad Aibling Station
Coordinates	47°52′46″N 11°59′04″E / 47.879444°N 11.984444°E / 47.879444; 11.984444
Type	Communications & Intelligence
Height	492 m (1614 ft)
Site information
Open to the public	no
Condition	dismantled, parts still in use
Site history
Built	1936/1952
In use	1952-2004
Demolished	2004

The Bad Aibling Station (abbreviated BAS, also known as Field station 81, which had an official designation as the 18th United States Army Security Agency Field Station, or as the pseudonym Hortensie III) is a satellite tracking station operated by the German intelligence agency Bundesnachrichtendienst (BND) in Bad Aibling, Bavaria.

Created by the Western Allies in 1947, it was run by the U.S. National Security Agency (NSA) until the early 2000s, when operations were gradually transferred to the BND due to public outrage over U.S. surveillance operations in Germany.

As part of the global surveillance network ECHELON, Bad Aibling is the largest listening post outside Britain and the USA.

In 1936 a military airfield was established by the German National Socialist government on the site of a sport airfield in Bad Aibling-Mietraching. After the Second World War, troops of the United States Army seized the military airport ("Fliegerhorst" and flight training base) that had evolved from the airfield. Initially, it was used by the occupying Americans as a camp for prisoners of war, a displaced persons camp, and as an orphanage under supervision of the UNRRA. Günter Grass and Joseph Ratzinger, later Pope Benedict XVI, are alleged to have met there as prisoners.

In 1952, the area was taken over by the US Army. Since a four-power agreement enacted Austria's neutrality in 1955 US listening devices that were situated there had to be abandoned. They were relocated to Bad Aibling and during Cold War the field station 81 was converted by the United States Army Security Agency ("ASA") to a central communications monitoring station for American intelligence.