Hey guys, just downloaded this classic and was shocked by the performance. Everything stuttered and the animations looked horrible. I found this fix and offer it from my google drive:

https://drive.google.com/file/d/1sYGlTPCjHMhjGR1tun6Y7e-XkFUy44QI/view?usp=sharing

Unpack the atdfix.rar and copy the two files into your game folder (yes, no files will be replaced).

Then rightclick on "Launch Airline Tycoon Deluxe" and set it's compatibility options to Windows XP (Service Pack 2).

Now you can start it from GOG Galaxy and it runs super smooth.

Have fun! :-D

Was just looking for a fix and this works perfectly (after disabling compatability mode).

Thank you friend.