美国空管软件 1N271 20U4 原因是 Without waming, at about 5p. m PDT, air traffic controllers lost contact with about 400 airplanes tey were Lacking over te soutweslennl US. A backup systeun that was supposed to take over in such an event crashed within a mimute after it was turned on. 空管软 件时钟 RB745 0L100 入 B757彬6710N 缺陷 F 737C-28 HO-REG I(LRR-PHNI Pln] B76764R EELL-KIRH美国空管软件 原因是 空管软 件时钟 缺陷