Character mistake: When McConaughey and Fox are at West Virginia University to ask their coaches for help with their offense, McConaughey is shown talking while looking at his reflection in a football trophy. At first his reflection shows him talking out of the left side of his mouth, but then he quickly switches to talking out of the right side of his mouth as he does throughout the entire rest of the movie.
Character mistake: In the references to Xavier, the coach character and the announcer pronounce it "Ex-Zavier." It's pronounced "Zavier." Make this mistake at their games, and you would be booed out of the stadium.
Answer: The did not mention it in the film, but here is a short explanation of what happened. The plane was on final approach, less than 6000 feet from the runway, and the weather was rainy and foggy. The tower communicated to the pilots that landing would be more difficult due to the weather and poor visibilty, but not impossible. The pilots couldn't see very well, and the plane collided with the tops of trees on a hillside located on the west side of the runway. The plane "inverted" and crashed almost upside down into the ground, creating a huge ball of fire and intense heat. The exact cause of the crash was never fully determined by the National Transportation Safety Board, although it was believed that the cause was due to "adverse operating conditions" and descent below "minimum descent altitude." (For more info, you can research "Southern Airways Flight 932")
Jazetopher