Can You Open a Plane Door Midflight? If You Can Lift Elephants

When a traveler unexpectedly tried to open a plane's exit door at cruising altitude during an

international flight last week, it took a crowd of passengers and the brute force of smashing two wine bottles over his head to subdue him, according to news reports. But perhaps unbeknownst to them, the passengers and plane crew also had physics on their side, an expert told Live Science. Even if the man had been left to his own devices, he would have needed to exert more than 23,700 lbs. (10,700 kilograms) of force to open the door — equivalent to lifting 4.5 Humvees or nearly two African elephants. [5 Real Hazards of Air Travel]