afan said:
Singer has said that SR would explore how Superman's strength would be employed in a "real physics" type environment. For me the plane rescue is an example of this exploration.
I think that's exactly what's going on. It seems as if he's initially more concerned about steadying the plane than anything else, because an out-of-control plane is just as likely to kill its passengers from all the knocking around inside as the crash will. The fact that Lois is only able to get to a seat and into a seatbelt after Superman's got the wing is a tip-off to his priorities.
A plane spinning out of control is nothing more than a dead weight. A plane, however damaged, that's been righted, still has both wings, and can be propelled forward is at least a plane that's generating a certain amount of lift under its wings. A plane doesn't fly because it has fuel; it flies because the engines can propel it forward at a sufficient speed to generate air pressure under and around the wings. Superman, as someone who flies regularly, would certainly know how air reacts when you're moving forward rather than down, so he's probably trying to push the plane forward in order to keep it more stable on the descent (and he's at least partially successful); that's gotta be why he's on the wing rather than under the plane. The wing's disintegration might be because of the plane's initial damage, but it might be because he can't propel the plane forward quickly enough to get the air to work with him rather than against.
I think it's a little bit like fighter planes trying to land on aircraft carriers. The Navy refers to these as "controlled crashes" because there's no question that the plane's going to be damaged after the maneuver (something like 10% of the airframe has to be repaired after a fighter lands on a carrier). The real question is whether or not an unpleasant procedure can be done safely enough that the people inside the aircraft stay alive.
So I don't think it may necessarily have anything to do with his absence from Earth, but more to do with the fact that Superman's trying to save a lot of people trapped inside a fuselage of unknown structural stability. At the speed the plane is already falling and the amount of damage it's already taken, his ability to save them has a lot more to do with what shape he can keep the plane in than anything else. Earth's gravity and physical laws may not apply to him, but they still apply to the plane and the people inside, and he's well aware of it.