Control has nothing special, use Trim to help you keep balance and use Yaw to keep it running straightly during take-off.
De-active AG 8 to maintain current flight attitude.
Active AG 1 and use Roll/Pitch to control C turret (last one on the plane).
that's all, but you might want to ask......

-What is "CARTEL warbird"

Cartel is a fictional faction in the video game" Greed Corp".
Greed Corp set in a world where land was separated by deep barrancaes, Cartel use these aircraft transporting troops to occupy and harvest resources around the world.

-WHY MAKE THIS

The artistic style of Greed Corp fasicnated me when I was young, but the style seems
didn't carried over to later works,developers have also been bought.
A few months ago, I saw some concept art of it by chance, it reminds me those happy old times……so, that's it.
I want to make a transporter at first, but just get this potato to fly consume lots of work, and until now I cant get it landing successfully even once.
Please let me know if you get it land, and I 'll be grateful if you have any suggestions to make it easier to control.

-Nothing else

So long