I lied about improved manouverability. Change the following in the autopilot PID
Pitch proportional from 2.8 to 3.8
Roll proportional from 1.2 to 0.8
Leave the rest behind and it should fly much better now.
Changes:
• Wing shape changed for better supersonic stability.
• Inlets and the wedge thing at the back changed for design purposes
• Manouverability has been improved with adjusted control surfaces and PID.
• Added flaps, use slider 1 to adjust.
Procedures:
This jet was designed to be controlled with the navsphere. Prepare for takeoff by locking the current heading, set the pitch from 9° - 15°, activate the engines and set throttle to max. Once in a good distance from the ground, retract the landing gear and choose your heading and after the jet is leveled with the horizon after the roll, set the pitch to 6° to set the angle of attack for a Mach 3 cruise and wait until it reaches the target speed. You might encounter some oscillation but it should be just minimal and won't affect your performance and roll sometimes will not level the plane with the horizon so I suggest manually doing it instead. Range with full afterburner is at around 1,300km but if you only keep the aircraft at high altitudes. Also keep in mind that this isn't as advanced with the lack of automated systems and advanced hardware and the result is this jet is very easy to stall so I recommend slowing down before taking sharp turns.
@FelixFan1 Well Thanks!