yup that weird thing on the sphear is anoying
To make a wake type effect, designe a few sprites with various stages of the WAKE effect, from start to when it disipates into nothing, then in game create a selection of plains (the same amount of plains as sprites) Then place the first plain textured with the first sprite behind the wing tips or were you wish to place the wake. Then as the plane moves forward place another plane at the wing tip coverd in the first tecture then chnage the prrevious plain for one thast textured in the SECOND texture, then as it moves forward again place another plain with the first texture at wing tips change the previous one to the second texture and the one before that to the third texture.
Keep doing this till all the textures are used, after that you need to errase the last plain each time.
the result will be...
As the aircraft moves forward the wake starts of at the wing tip and expands and fades as the aircraft flys, the whoel process is constantly placeing the first texture at the wing tip and changeing each of the follwing tectures to the next texture untill it finally diapears.
Ok now i know i really confused the hell out of you now
Its kinda hard to explain really, hope you kinda got the idea.