About this scene:
After losing his duel with Darth Vader as well as his hand, Luke has plunged to his apparent death from a Cloud City gantry platform. However, he has been sucked into an exhaust chute and now hangs precariously below the city. He calls out to Leia, who hears him and heads the Milennium Falcon back to rescue him.
Most of this scene still remains in the film, but there was some additional footage detailing Lando's rescue of Luke after he climbs out of the Falcon's hatch and onto the top of the ship, as well as some description of the scene in an earlier version of the script.
Some photos are from the LucasArts Behind The Magic CD ROM, some from the Star Wars Insider. One of the trailers for The Empire Strikes Back actually contains just a few frames more of Lando exiting the hatch.
EXT MILLENNIUM FALCON HULL - CLOUD CITY - DUSK
The hatch pops open with a hiss of pressure. Lando reaches out to help the battered warrior inside the ship. Suddenly, there is a huge explosion near the ship causing it to lurch wildly.
Luke is almost thrown overboard, but Lando grabs his hand in time.