As it turns out, cyber-hijacking of airplanes has been around for over a dozen years. For your consideration:
When the attacks of 9/11/01 are mentioned, I think of the 9/11/01 horoscope with Mercury (travel) conjunct US natal Saturn (authority; stability, @14Lib48) rising, all at '15 Libra' = "Circular Paths"--note this discussion of airplanes expertly turned from their paths such as the one that hit the second Tower--and including Malaysia 370. This presentation also reminds me of the void-of-course Moon on the morning of 9/11/01 and its implications that something put into action could not be interfered with...such as the course-change a computer-hacked plane would experience.
Transit Mercury to natal Saturn denotes a time of seeking or using information and skills in order to attain a more senior or authoritative status. Remember that Bush and Cheney were recently installed in the White House and were spoken of as "illegitimate" after Justice Rehnquist placed them in office in December 2000 after the bogusness of Jeb Bush's Florida election.
Serious pursuits are also indicated by Mercury to Saturn along with a hint that the preparations for 9/11 were a long term enterprise which resulted in a restriction of ideas and communications--such as police phones that didn't work properly that morning, the often touted inability to "connect the dots" between the FBI and CIA, and the silencing of dissenting journalists and others since that day.
'15 Libra' from The Sabian Symbols in Astrology by Dr. Marc Edmund Jones; "Keyword: CONGRUITY: a rather extraordinary facility in self-adjustment or practical reorientation." I'll say! After all, it was the 9/11 attacks that allegedly made the US Patriot Act implementation and all the subsequent cyber surveillance by The State 'necessary', sans the US Constitution.