It's everyone's most sane people's worst nightmare to have something terrible happen mid-flight.

At 40,000 feet in the air, you're pretty much at the mercy of whoever's in control of the plane, as well as a hefty dose of good luck.

The passengers on the United Airlines flight from San Francisco had just that yesterday, when the pilot was forced to make an emergency landing at Honolulu because one of the engines basically started to break up. More accurately, the cowling around the engine broke off, leaving the engine itself dangerously exposed.

One passenger reported that they heard a 'big bang' and then the plane started to shake violently.

Several of them shared photos of the engine, while there is one video that would put the fear of god into you doing the rounds. Imagine looking out the window and seeing this?

 

Talk about scary.