Help Needed for sky issues

Hi everyone,

I recently re-uploaded this night shot after enhancement made due to previous rejection. Here is the link of the enhanced photo.

Second upload: http://www.airplane-pictures.net/images/rejected-images/2017-3/867041.jpg

First upload: http://www.airplane-pictures.net/images/rejected-images/2017-3/866640.jpg

It is rejected due to grainy sky.

Here is my editing flow,

- Lr adjust basics and levelling

- nikcollection for more detail edits

- nik dfine2 to clean up the noise and sky

- high pass filter for sharpening with brush tool.

I actually used dfine2 3 times. First time applied on the entire image; second and third time applied and focused on the sky and some areas with potential noise.

I really need your help if you have any suggestion to make this image better. This is not a super creative or newsworthy image but I take every upload and opportunity as practice.

Thank you very much for your time to read this post. I really appreciate your help!

On a 4k monitor I see very little wrong with either.