We recommend starting with the aircraft tutorial that introduces the aircraft development process step by step. Creating a new aircraft can be split into two major objectives: the creation of the 3D model and the definition of the aircraft.
Aerofly FS 2 uses an object-based approach to simulate an aircraft for maximum flexibility. This means that each aircraft is defined in terms of many objects (also called (function) blocks or elements in commercial general purpose simulation packages), instead of a fixed set of variables that describes an aircraft as a whole. In short this means that there are a lot of building blocks that all work together to describe the aircraft. In addition to very general objects that can be used for any type of simulation, there are many objects specialized for flight simulation like aerodynamics forces, engines and propellers, avionics objects and many more. The programmer of the aircraft is free to add any number of objects and connections to an aircraft by adding it to the dynamics section of the aircraft's .tmd file.
Please refer to the Aircraft Definition page of this document for further information.
The Aircraft Converter that comes with this SDK is the same tool we use to convert aircraft. There are no limitations on objects or functions you can use to create your aircraft.
However, the SDK doesn't support custom display programming yet. While you can re-use all existing displays, there is currently no way to get your display code into the simulator. This might be addressed in future versions of the SDK. Please contact us directly if you want to implement custom displays.