Russian Plane's Cockpit Voice Recorder Captured 'Noise' in Final Second

— -- A noise was heard in the final second on a cockpit voice recorder recovered from a Russian plane that crashed near a resort city on the Red Sea last weekend, killing all 224 people on board, said an Egyptian official heading the committee investigating the crash.

Ayman el Mokadem cautioned Saturday that no major conclusions could be made about the cause of the crash, which resulted from the plane breaking up in midair. The Metrojet plane crashed shortly after taking off from Sharm el-Sheikh last Saturday.

Mokadem said the flight data recorder stopped about 23 minutes after takeoff when the plane was at an altitude of over 30,000 feet and traveling about 323 miles per hour. The wreckage was scattered over eight miles, indicating the plane disintegrated in midair, he said.

To determine what caused the final noise on the cockpit voice recorder, investigators may have to pour over each millisecond of sound as they look for clues into what caused the crash, according to Tom Haueter, the former director of aviation safety at the National Transportation Safety Board.

An extremely loud noise like an explosion or rupture would be heard as a “click” on the recording, Haueter said. Investigators then break that “click” down into milliseconds to see if the sound profile appears to be a bomb, fuel tank explosion, rupture or other event.

Since the crash, the United Kingdom and Russia have suspended flights to and from the resort city.

The U.S. Department of Homeland Security has since announced new security enhancements for commercial flights bound for the U.S. from certain foreign airports Friday, including expanded screening to items on planes and offering assistance to certain foreign airports, though further details weren't released.