Star Wars films are broken down into Acts.

In ANH you have Leia captured and sending the droids to Tatooine where they meet Luke, Ben and Han.

That's a first Act.

Then you have our heroes on the Death Star finding the Princess, Obi-Wan and Vader fight and they escape.

That's a second Act.

Then you have the arrival at Yavin, the launch of the fighters the battle and the destruction of the Death Star.

Each Act has a conclusion which has to be dramatic.

So end of Act One the fight past the Destroyers into Hyperspace.

End Of Act Two the Tie Fighter attack.

End Of Act Three the celebration, the conclusion of the film.

Act one of ROTJ is the rescue of Han it has to be a major set piece to draw a line under the end of the Act so the audience can move onto the next part of the story.

If you skimp on that you cheat the audience.

One of the problems with the PT was the poor stucturing of most of the Acts.

Act One of the ROTS was possibly the closest we got to that traditional structure.

When the ship crash lands it feels like a mini-ending to a mini story.

The conclusions to the first Acts in TPM and AOTC is less easy to define.

The Queen's ship jumping into hyperspace happens too soon in the movie and it's hard to tell what the act one ending of AOTC's is.

Mess with the story structure at your peril (besides with all it faults it still the best paced part of the film).