Unused graphics: Tornado's shadow

As a change of pace, I thought it'd be nice to look at some of the graphics which go unused in the game. Below are the full contents of the Tornado art file used in Angel Island Zone's intro. Yes, Tails' head is baked directly onto the plane.

Surprisingly, the landing gear and rocket are separate sprites just like in Sonic 2, even though both of them are always attached to the plane in Sonic 3. More surprisingly, however, are the black oblong shapes at the end of the art file.

No objects in the game's code use these sprites, so one can only speculate about their intended use. My guess is they were meant to form a shadow, cast by the plane onto the ocean surface below. Here's a mock-up animation illustrating what it might have looked like:

Why this effect wasn't used, we will likely never know. Perhaps the developers weren't happy with how it looked. It does look rather strange; no other objects in the game cast any shadows, and it may have been too strange that Sonic didn't cast a shadow once he jumped off the plane.