Butter-Side Down

In the stunt known as a Long Fall, the stunt man will always fall backwards because the safest way to land on the airbag is on his back. The classic effect is achieved by filming the falling stunt man falling from above as he drops into the distance, smashing onto some surface that looks solid. Often this shot is followed by a closeup of the actor lying on the damaged surface, occasionally the roof of a car. Falling backwards also makes it easier to shoot back at whatever knocked you over the edge, though this is often accomplished by catching the stunt man (or even occasionally the actor) on a cord which is digitally removed in editing.

This trope has seen so much use that it may have become a Dead Horse Trope. Digital editing makes all sorts of falls possible now and few viewers are stunned by the long fall.

As a Death Trope, Spoilers ahead may be unmarked. Beware.

Examples of Butter-Side Down include:

Film

The canonical example of this is Burt Reynold's movie Hooper, in which he plays a stunt man (almost a lampshade hanging), but examples abound from adventure films going back to the early 1970's.
The Poseidon Adventure had a cliched example of that (repeated endlessly in the trailers) during the rollover sequence when a man falls from the "floor" to fall into a stained glass "ceiling." The air bag lay just underneath the sugar glass.
Turk 182 has the canonical example of the car-roof fall during the opening sequence.
Crank: In the end, Jason Statham's character falls from a helicopter and in an odd Double Subversion lands on a car on his side, then bounces off and falls on his stomach.
Almost every adventure film created between 1970-1990.
A zombie in Zombieland is kicked off the tower drop ride during the climax and is shown flailing and splattering on the ground. The DVD extras include a section on how the stunt was performed, showing the original footage of the stuntman swinging back on a rope and how the digital effect was made and added into the fall.

Live Action TV

Doctor Who, Logopolis.
Locke's paralyzing fall in the Lost episode "The Man From Tallahassee."
In the season 5 finale of Buffy the Vampire Slayer, Spike is thrown off the top of a rickety structure to fall about five stories. They don't actually show the fall from top to bottom—but, as James Marsters notes, the final shot of his stunt double doing a face plant for the final six feet was real.