Finding downed jet in open ocean is a tall order

Though searchers believe that they have found debris from an Air France jet that disappeared off Brazil's coast Monday, finding the entire plane and learning exactly what downed it could be a tedious, years-long process.Many factors can complicate a search effort. Tradewinds and ocean currents can quickly scatter wreckage across several square miles, and the plane's altitude -- almost 7 miles, in the case of Flight 447 -- can make it difficult to pin down where the aircraft hit the water."It's a big ocean," said John Hansman, director of the Massachusetts Institute of Technology's International Center for Air Transportation. "Once you're offshore, you're no longer in direct radar contact."It varies from airline to airline, but passenger jets generally send location reports every few hundred miles when they're over open water, Hansman said.They also send out maintenance reports via satellite that provide the plane's location at a specific time. Some maintenance reports are routine; others are sent when a problem or malfunction is detected, Hansman said.