I proposed the idea to this thread to encourage group discussion as well as generate ideas for a Movie I am writing.

In this movie a disgruntled and underpaid software engineer that created the Unmanned airliner's artificial intelligence decides to sell the software technology to a terrorist organization. This allows the terrorists to hijack every single unmanned airliner. This includes 600+ airplanes in my story. I'm just looking for a realistic timeline for this to take place.

Sorry if the idea of terrorist hijackings offends but the movies that sell tickets have some kind of messed up characters trying to cause havoc.