I'm a Canon regular user but I sometimes use the D800E coupled with a 24mm for window views or 70-200mm for other aircraft shooting.
This combination is perfect for general aviation around airports, landing, takeoff or taxiways, but concerning airshows, acrobatics or military aircrafts, a much faster body is required.
For window views this body offers the ability to show many ground or clouds details.
Concerning the post-processing with the D800, don't think about cropping, the first rule for good photos is to shot always in FF
and in RAW.
If you have in first position another photo interests like landscapes or studio uses, buy this body, you will be very satisfied and then in a second position use it for aviation.
Finally you must have a lot of RAM and Hard disk space on your computer, files are huge.
some examples with the 24mm:
some examples with the 70-200mm: