Investigators have recovered the cockpit voice recorder (CVR) from the crashed Air India flight, a key step in uncovering what caused last week's deadly accident. The London-bound Air India aircraft,

Air India and Boeing are in the midst of significant turnarounds, but knowing the cause of the crash of Flight 171 will take a lengthy investigation.

An Air India crash Thursday involved a Boeing 787-8 Dreamliner, which the aircraft manufacturer first delivered 14 years ago.

Indian authorities have ordered what they called “extended surveillance” of all Boeing 787 aircraft in the country’s fleet while they investigate the cause of the Air India crash.

The event, which runs from June 16 to June 20, is the industry's largest trade show, where many aircraft orders are typically placed by airlines.

As the investigation continued Friday into the horrific Air India Boeing 787 Dreamliner crash that killed at least 290 people, the sole survivor is doing well but is "psychologically disturbed."

The crash happened just weeks after the company cut a deal with the U.S. government to avoid taking criminal responsibility for a pair of deadly crashes in 2018 and 2019.