An engine has exploded mid-flight on a Southwest Airlines flight from New York to Dallas, leaving one person dead and causing a passenger to be partially sucked out of a broken window.

A flight attendant for a major US airlines says she caught two pilots streaming hidden-camera footage into the cockpit — live — from the aeroplane’s bathroom.

Attendant Renee Steinaker alleges in her lawsuit that she discovered the sick surveillance during a 2017 Southwest Airlines flight from Pittsburgh to Phoenix, Arizona Central reported.

At some point during the flight, the pilot, Captain Terry Graham, asked her to come to the cockpit so he could go to the bathroom, the suit alleges.

There was nothing unusual about the request, as it’s Southwest Airlines policy that two crew members be in the cockpit at all times, the suit explains.

What was unusual was what Ms Steinaker says she saw when she got to the cockpit.

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Ms Steinaker noticed an iPad on the windshield showing a livestream video playing on it of Mr Graham in the bathroom, according to the report.

The captain’s co-pilot, Ryan Russell, panicked when he realised she noticed the device, the report said.

Mr Russell claimed it was part of a new security measure featured on all Southwest flights, Arizona Central reported — but the flight attendant wasn’t fooled.

Ms Steinaker snapped a photo of the iPad and alerted her superiors when the plane landed.

“The safety and security of our employees and customers is Southwest’s uncompromising priority.

“As such, Southwest does not place cameras in the lavatories of our aircraft. At this time, we have no other comment on the pending litigation,” the airline told the publication in a statement.

This article originally appeared on the New York Post and was reproduced with permission