NBC News Dateline reports on "a simple, yet deadly problem: mis-communication between commercial pilots and air traffic controllers." The investigation reveals that although "English is the defacto language of aviation, ... a lack of oversight has led to a breakdown in simple communication." It documents how poor language skills have hindered communication between foreign pilots and U.S. controllers, as well as between American pilots and controllers abroad. The report shows that the problem is widespread, because the Federal Aviation has failed to enforce a standard. The investigation uncovers a tape "that documented how poor language skill contributed to the crash of an American Airlines plane into the side of a mountain in Cali, Columbia." It also details numerous differences between the standard aviation phraseology in the U.S.A. and the rest of the world.