The background used in the title screen of Pilotwings (for SNES), it's a simple sky background with clouds. Includes a fake HDMA too.
If want to use it in a level, I recommend you to use a layer 3 background, since the background is a bit empty on the top.
The first screenshot for me is one of those "pictures you can hear." I loved Pilotwings! That's a plane moving in the sky so I feel this is more ideal for a scene that is intended to be still-frame, although just using the other components leaves it open and normal for a level. Quite a comfy oceanside cloud background. (It almost makes me want to shoop that "SUPER MARIO WORLD" into "CHEMTRAILS" with Pilotwings font now that I am noticing that plane, hehe)