It was about time we had Donnie Darko on the Black Box. It is a very interesting case - not so much for a complicated time-travel loop or paradox, but rather for the way it tries to fit a simple situation into a coherent description of Time-travel that combines real science with a fictional framework, described in the book "The Philosophy of Time Travel" that appears in the film (in particular detail in the Director's Cut).
The information given in the Director's Cut and official websites does not give a unique and exhaustive explanation of the events. In fact there are various interpretations out there that are consistent with the film. I would like to point out and comment two.
In terms of time travel, once the disruption has happened without explanation, it is clear that the future is not set in stone, and if it has changed for the worse (jet accident) then it could at least changed again in order to mitigate the devastating effects. With the help of time travel, Donnie and his helpers, try to break the time loop that has been generated, not by avoiding that the falling jet engine travels to the past, but by making it travel to the past again. The originally generated time loop is closed and self consistent, but by breaking it, a linear timeline is restored (jet travels through time, but no accident occurs later), which is different from the original one (accident, but no jet traveling though time), but at least better that the one with the embedded time-loop (accident and jet travelling through time). Don't these three options remind you of a Moebius strip?