[DTA]

The concept is much older. In 1978 ex-CIA hitman Nikola Kavaja hijacked a Boeing 707 airliner in NYC. Objective - to fly it to Europe and smash it into skyscraper that was symbol of Dictator Tito's Communist regime. His plan soured and he got 20 years in prison.

There was also another older movie, cannot recall it's name, about Air force One being hijacked for the same purpose.

There is only one problem with the concept of airliners being used as a missiles. Their engines compress air. Due to air density close to the ground, when they fly at very low altitude they can not fly faster than 250 knots. The only way to gain high speed at low altitude is to nosedive them from cruising speed at high altitude, but they would probably disintegrate mid-air. So airliners as missiles is is mostly Tom Clancy/F-X territory.

[cynwoody]

There is only one problem with the concept of airliners being used as a missiles. Their engines compress air. Due to air density close to the ground, when they fly at very low altitude they can not fly faster than 250 knots. The only way to gain high speed at low altitude is to nosedive them from cruising speed at high altitude, but they would probably disintegrate mid-air. So airliners as missiles is is mostly Tom Clancy/F-X territory.

Not true. United 175 was doing 469 knots when it hit WTC 2, about 87 knots faster than AA 11 hit WTC 1. That's according to NIST (see here (18mb PDF), page 38). Flight 175 made a rapid descent after it was hijacked (about 5000 feet/min — faster than Germanwings), but there was no "nosedive". It was in more or less level flight when it hit.

https://www.youtube.com/watch?v=K4vvVyKyy0k

[cynwoody]

In 1978 ex-CIA hitman Nikola Kavaja hijacked a Boeing 707 airliner in NYC. Objective - to fly it to Europe and smash it into skyscraper that was symbol of Dictator Tito's Communist regime. His plan soured and he got 20 years in prison.

He got 67 years, but only served 20. Interesting story.