Boeing 787 Nosedive Likely Caused by Flight Attendant Bumping Cockpit Switch

An innocent flight crew mistake is likely what sent a Boeing 787 Dreamliner into a nosedive that injured dozens of passengers on a LATAM flight this week ... according to a new report.

The Wall Street Journal says the preliminary evidence points to an incident in the cockpit -- while serving a meal, a flight attendant accidentally bumped a switch on the pilot's motorized seat ... pushing it forward and sending the plane into the nosedive.

The switch has a cover that's supposed to prevent this kinda thing from happening while the pilot's seated, according to the WSJ report, but clearly something malfunctioned ... or it's a horrifying case of operator error.

As we reported, the Chile-based airliner was flying from Australia to New Zealand on Monday when it started plummeting, pinning several passengers to the cabin ceiling. The pilot was able to regain control and they landed in Auckland, where 50 people were treated for various non-life-threatening injuries.

Authorities took the black boxes off the plane on Tuesday to begin their investigation.

Here's what's really interesting -- according to passengers, the pilot said the cockpit instrument panel had suddenly gone black for a few moments as he tried to explain what went wrong.