jetliner, the window- counterparts at the Berlin Air Safety Center seat passenger can see the Berlin Wall three (BASC). The BASC monitors the plane traffic in times. Heading east, he first glimpses the bar- the 20-mile-wide air corridors that link West rier where it runs between East Germany and Berlin and West Germany. West Berlin. From an altitude of several thou- "Since we're in the same room around the sand feet, the broad "death strip" looks as be- clock, our shift work becomes...