0 CAN YOU OPEN THE EMERGENCY DOOR OR ANY DOOR OF AN AIRPLANE DURING MID-FLIGHT?

No.  It's highly unlikely.

Sure we've heard many stories of people trying to open plane doors during flight - but no one has really ever succeeded - only in the movies!

One cannot open the door of a modern, pressurized commercial jet in midair..

The reason: doors won’t open in mid-flight due to pressure, and because of the way plane doors are constructed.

The aircraft doors in question are “plug type” doors, meaning “When closed, [these doors] are larger than the openings. You can push on a cabin door all you want, but it’s not going to go through the smaller opening.”

So how does one ever get this door through the opening if it's too small? There is more than one door model, but generally there's a handle that is rotated. The operator must pull the door slightly inward, reposition and rotate it before it can pass through the smaller opening.

Also, once all the doors are shut and the plane is starting to taxi down the runway - the cabin will start to pressurize.

Pressurization exerts a very strong force against the inside of the plane, sealing the doors shut and preventing them from being opened in flight. You can twist the handle and tug on it all you want, but it's impossible for a human, or even several humans, to overcome this pressure. Still, it's not recommended that you play with the door handle at any time as unauthorized tampering with aircraft equipment may result in arrest..

Some aircraft models have doors which slide upward on the inside of the aircraft, but the premise is the same: When the door is closed, it's larger than the opening, and cabin pressure prevents it from being opened in flight regardless of whether the handle is manipulated.

There was an incident of a door being unlatched in 1989, of the lower cargo door on a United Airlines passenger jet at about 23,000 feet which caused a sudden and explosive loss of pressure which in turn torn open a portion of the cabin— sucking out nine passengers through the large hole, along with their seats and the floor around them.  However, not because of someone trying to open the door but rather due to malfunctioning in the door’s electrical locking mechanism.
Modern doors today have been better re-designed to prevent this from happening. 





Source(s):  farecompare.com, usatoday.com