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.

Boeing has pulled out of this week’s Paris airshow, which is traditionally an important event for aircraft manufacturers to announce big orders, saying it would instead focus on the investigation.

It could take months to fully understand what went wrong in the crash, the first involving a Dreamliner. Officials from India continued the investigation Friday.

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

An Air India Boeing 787-8 flight headed for New Delhi returned to Hong Kong shortly after takeoff Monday because of a "technical issue," Indian Media reported.

A helicopter crashed in the northern Indian state of Uttarakhand on Sunday, killing seven people on board. Local officials said the aircraft was flying from the town of Kedarnath to Guptkashi, which is a prominent Hindu pilgrimage site in the Himalayas.

A tragic helicopter crash near Kedarnath in Uttarakhand has claimed the lives of seven people, including two children. The incident occurred early in the morning around 5:00 AM when a helicopter carrying pilgrims from Kedarnath temple to Gaurikund lost control and crashed near a hilly area close to Gaurikund.