Performing a Test Flight

At some point—any point you choose, really—you will need to bring your aircraft into X-Plane and test it out. A typical test flight might include:
 * checking all control surface movements (by switching to an external view and giving full deflection in each direction for all controls),
 * noting the aircraft’s ability to fly straight-and-level (how much trim it requires, etc.),
 * confirming that the center of gravity feels like it is where it should be, and
 * checking the lift and drag vectors (by pressing the keyboard’s / key by default) and confirming that they appear as expected.

Ideally, when performing a test flight, you will have enough experience with the real-world version of the aircraft to know how it should feel. Following a test flight, your goal is to be able to go back into Plane Maker and track down the source of any inaccuracies.

When modifying the flight model to match real-world performance, be careful that you do not modify your aircraft in a way that ignores the real-world meaning of the parameters you are changing. Even in the (unlikely) event that this is an acceptable fix at the moment, you risk degrading the quality of your aircraft in future versions of X-Plane.

For instance, suppose that, for some reason, your plane feels sluggish when turning. You might try increasing the area of the control surfaces, knowing that you had already matched the size of the real-world control surfaces, and find that the problem goes away.

This is absolutely not way to go about changing the plane’s flight characteristics in X-Plane. The control surfaces’ area does not simply represent a variable that can be changed to affect how a plane turns. The surface area must match the way the real-life airplane is built. If you increase the area, straying from reality, to “fix” a problem, what you really do is create a new problem later when X-Plane goes to simulate your model.

Simply put, if you put intentional errors into your plane’s flight model to compensate for limitations of the simulator, any future improvement in the simulation accuracy of X-Plane is almost guaranteed to make your plane fly worse in the future.