Long as we're talking about crashes in SW...

[Kurgan]

Can anybody calculate the force that occurs when Luke crashes into Dagobah swamp in his X-Wing and when he crashes his Snow Speeder on Hoth?

(Hmm... seeing a pattern here)

According to some people, he shouldn't have survived either one, even with that plastic helmet. Comments?

And what happens if a Rebel pilot needs to eject?

I know in some of the comics they show Luke doing work on the outside of his X-wing (I guess R2 could do his job?) and suddenly he has a full face mask (and sealed pressure suit?) with oxygen on his helmet.

The fact that the X-wing has "wings" implies that it's used inside planetary atmospheres periodically, so then you'd think ejection would be an option, but we never see it, so I wonder... and Snowspeeders even more so.

[Eframepilot]

We have no idea on how hard Luke hit the swamp on Dagobah, as we saw it from inside the cockpit. Seeing as the X-Wing didn't hit the bottom of the swamp and embed itself in the mud, it couldn't have been very hard.

The snowspeeder crash is slightly more objective since we could sort of see the crash. Again, the snowspeeder not burying itself in the snow and/or sliding across several miles before coming to a rest points to a low velocity on impact. Perhaps Rebel craft have some sort of repulsorlift emergency brakes or something that slow crafts down right before or at the moment of impact using inertial damper tech.

On ejection: The flight suit actually closes upon ejection in space to become a functional space suit. Hard to believe from the appearance of the flight suits but true.

[Sarevok]

X-Wing fighters are fitted with intertial dampners that can protect pilots from thousands of gees of acceleration / deceleration. This is what probobly protected Luke.

[Mad]

Can anybody calculate the force that occurs when Luke crashes into Dagobah swamp in his X-Wing and when he crashes his Snow Speeder on Hoth?

(Hmm... seeing a pattern here)

According to some people, he shouldn't have survived either one, even with that plastic helmet. Comments?

I figure the inertial compensators on the X-wing let him survive, and it's likely that the airpeeders also have compensators. Luke wouldn't have felt the full brunt of either crash.

And what happens if a Rebel pilot needs to eject?

From the X-Wing novels, they have a "MagCon field" generated by the suit that keeps the air around him... doesn't last long, but can allow for the pilot to be picked up by a shuttle.

so then you'd think ejection would be an option, but we never see it, so I wonder...

Considering that Porkin's reply to Biggs ordering "Eject!!" at the Battle of Yavin was something along the lines of "I can hold it!" and not "I can't you idiot!" I'd say that X-wings have an eject function. (Though one wonders what good ejecting meters above a space station that's targetted for destruction would really do...)