'Signal Detected"

Possible underwater signal from EgyptAir flight detected

Cairo (CNN) A French naval vessel has detected an underwater signal that could have originated from one of the so-called black boxes of missing EgyptAir Flight 804, according to the Egyptian investigative committee.

Specialized locator equipment on board the French vessel La Place has detected a signal from the seabed in the search area in the Mediterranean Sea, the committee said in a statement.

The signal is "assumed to be from one of the data recorders."

La Place is part of the team of vessels involved in intensive search operations to find the flight data and cockpit voice recorders from the Airbus A320 aircraft. The recorders could reveal evidence about what caused the crash.

Flight 804 crashed May 19 in the Mediterranean en route from Paris to Cairo.

Authorities hope to recover the data recorders, so a specialized vessel managed by the Deep Ocean Search company can then retrieve them. That vessel is set to join the search team within a week, the investigative committee said.

It isn't the first time investigators have said they detected a signal from the plane.

Last week a lead investigator in the search said airplane manufacturer Airbus had detected signals from the plane's Emergency Locator Transmitter, a device that can manually or automatically activate at impact and will usually send a distress signal.

The signals gave investigators a more specific location to detect pings from the black boxes, state media reported.

The data records have been fixtures on commercial flights around the world for decades.

The flight data recorder gathers 25 hours of technical data from the airplane's sensors, recording several thousand distinct pieces of information. Among the details investigators could uncover: information about the plane's air speed, altitude, engine performance and wing positions.

The cockpit voice recorder captures sounds on the flight deck that can include conversations between pilots, warning alarms from the aircraft and background noise. By listening to the ambient sounds in a cockpit before a crash, experts can determine if a stall took place and the speed at which the plane was traveling.

But black boxes aren't perfect. In several cases -- such as the 1996 crash of TWA Flight 800 or the crash of American Airlines Flight 77 on September 11, 2001 -- authorities had hoped to find clues in the recorders, only to discover that the data inside had been damaged or the recordings had stopped suddenly.

-CNN-