From 01:35:50 for about 20 seconds you can see the fateful airplane accelerate down the runway with the flaps completely retracted. This is exactly what happened to the real WRZ flight and caused the takeoff to fail. It is a deadly practice and must have been staged exclusively for that scene to be shot. No doubt the plane deployed the reverse thrusters and brakes to slow down before the end of the runway after the shot ended.
Director Enrique Piñeyro, is a real pilot, who used to work in LAPA before leaving the company. The movie shows his struggle to make the company to see what was about to occur if the safety policies weren't revised. He said several times in the movie, and in real life, that a fatal accident was about to happen. His prediction became real in 1999.