In February 2009, Continental Flight 3407 crashed outside of Buffalo, NY, killing 50 people. The flight was operated by Colgan Air, a regional airline that flies routes under contract for US Airways, United, and Continental. The crash and subsequent investigation revealed a little-known trend in the airline industry: Major airlines have outsourced more of their flights to obscure regional carriers.

In this video chapter from FRONTLINE  Flying Cheap, correspondent Miles O'Brien explores this trend and examines some of the many factors that may have contributed to the accident.