In the movie, the terrorists (the "anarchists") simultaneously hijack three civilian airplanes and load them with nuclear weapons, while blowing out of the sky three other aircraft. The first three aircraft then assume the "identity" of the three destroyed planes and the terrorists then plan to crash the nuclear-armed craft into three major cities. Unlike on Sept. 11th, however, fighter planes successfully intercept and destroy the suicide planes.
As I said, not identical, but close enough to send shivers down one's spine. That's really the only reason to ever watch this otherwise pretty standard sudser.