To say that will be difficult is an understatement. They could be at the bottom of the ocean -- two miles down.
As CBS News correspondent Nancy Cordes reports, experts think there's a better way to get valuable data.
When airliners go down, their black boxes nearly always provide the critical clues to what went wrong.
If a black box is damaged or can't be retrieved, those secrets go down with it.
In this age of satellite technology, some experts question why airplanes can't beam cockpit conversations and flight data directly to a storage facility via satellite. Thus creating a real time record of the plane's operations.
"I think it is time that we look for some alternatives," says Pete Goelz, former managing director of the National Transportation Safety Board.
"People raise the issue of cost. But think of the tens of millions of dollars that are being spent right now mounting this search today in the South Pacific," said Goelz.
It's a search that may prove fruitless. Investigators never found the black boxes from the planes that crashed into the world trade center on 9/11.
Still, downloading data from the thousands of airplanes that are aloft at any one time would be an enormous undertaking.
"We currently don't have the technological wherewithal for an aircraft to transmit that much data continuously," says Dan Elwell, vice-president of the Aerospace Industries Association.
And there's another problem. Pilots unions have long objected to more monitoring of flight crews. As they did when Colgan Air proposed randomly sampling cockpit recordings from flights to check for excessive chit chat after the February crash in Buffalo, N.Y., which killed 50.
"They believe they deserve and need some degree of privacy,'' said Goelz.
The question is, could a system be designed that wouldn't break the bank and would ensure that the data would only be examined if there was an emergency in flight? Or it may be that current black boxes need to be beefed up, made floatable or have their signal beacons last longer.