Air France jet crashed vertically, black box hunt to continue: Investigators

But Bouillard said the sensors were a "factor but not the cause" for the crash.

Some of the messages transmitted by the Air France plane mentioned inconsistent speed recording from the external speed sensors (Pitot tube). This led numerous analysts to predict that the pilot could have set an incorrect flight speed based on the readings from the faulty Pitot tube.

Black box search to continue

Bouillard said that the search for the black box will continue for 10 more days till 10 July.

The flight recorders also known as the black boxes emit locator signals called "pinger" that can be picked up underwater listening devices. However, the battery powering the signal can last up to 30 days. The 30 day time limit expired on 1 July, despite the setback the search will continue till July 10.

The hunt for the black box is spearheaded by a French submarine backed up with other ships. A powerful underwater listening device provided by the U.S navy is also used to pick up the "pinger" signals emitted by the black box.