sentences:  In order to protect the vital Air Transport Command South Atlantic Air Route to Europe and North Africa, Sixth Air Force combat units were stationed in Brazil to patrol the South Atlantic air routes.Sixth Air Force had the responsibility for tracking down submarine wolfpacks, which consisted of groups of three of more subs attacking Allied shipping using a strategy now known as "Search and Destroy".As most shipping in the Caribbean was not in defensive convoys, aerial surveillance of the area was crucial to their safety.