One advantage with the DSLR over a point and shoot is when you push the button, you get an instant picture. No waiting. In fact if can shoot about 6-10 pictures per second if you want. The sensor on the DSLR is larger than on the point and shoot. What that means is if you have a DSLR and P&S with the same DPI, you the larger sensor on the DSLR will give you a larger file allowing you to zoom in by cropping.
Though your original post was what DSLR was a good choice, it may not be for shots from an airplane. The disadvantage is it is larger, heavier, you need more lenses to get much of the advantage, and may be more trouble than it is worth in an airplane.
If you are spending time and effort to make sure you have a light airplane, adding a pound or two for a camera may not make sense. You will get great photos with about any camera out there. If you want to experiment with settings, speed, and lenses, the DSLR is the way to go. Quick and easy - the P&S.