The contrast is OK, I believe, but I think that your rejection might come from the fact that the a/c is completely black and due to the addition of contrast on your edit it might have lost some quality.
My humble opinion.
"Faithless is he that says farewell when the road darkens." J.R.R. Tolkien
Thanks guys. I've backed off a bit on the contrast, sharpened it a bit more and re-uploaded it. I find that there is often a fine dividing line between soft and over-sharpened. I had one photo a few weeks ago rejected because it was soft and also had the jaggies. I never did figure out what to do about that.