Looks more like smoke out the back to me, the VT's would be off the wings??
A Nice shot mate.

And I'm not one for clouds on display shots, but in this case, maybe a little white haze for cloud.

She's a beautiful image, IMHO, c9f! Very strong composition and excellent use of dominant and recessive colors! 

The sky looks fine to my eye as there is a gradient both from top to bottom and from left to right. IMO, any more than that might muck up the smoke. 

A couple of thoughts for your artistic consideration:

1) The light is coming from the right as evidenced on the center and left aircraft. However, the light on the right aircraft is coming from the left! That sort of thing can make people "feel" uncomortable with an image, even though they may not be able to immediately put their finger on why that is.

You might, as an experiment, try darkening the underside of the right aircraft, matching the shadow side of the center aircraft, and making the side toward the light a bit lighter. See if you think that looks better or worse to you.

2) Canopies! Often ignored, a potential pain in the butt and often make an image "feel" not right! There are a number of ways to make the sky appear to be showing through the canopy, WITHOUT having to cut things, and still retain the nice reflections. If you are interested, PM me and I'll provide you with a few methods for your consideration. 

You have a good eye for composition and color, M8! That is the hard part! Messing with a few technical things is the relatively easy part of making a good image, IMHO.

Cheers,
K. H.

You have mail, M8!