There is no simple answer to this question as it depends on the particular model and how it is constructed. Some Guillows models do fly, while others do not.
A quick look at the various construction materials used in model aircraft will help to explain why some models fly and others do not. Traditional balsa wood and tissue paper models are very light and delicate and are not very suitable for flying. They are more suitable for static display. better materials such as fiberglass, carbon fiber, and Kevlar can be used to build heavier and more robust models that are better suited for flight.
While a heavy model is more likely to fly, it is not always the case. Some of the lighter models, with the right construction and design, can be just as successful in the air. It is important to test the model before flying it to make sure that it is stable and will not crash.
I have been building Guillows model airplanes for many years and have had great success with them. There are a few things that I have learned that can help make the experience even better.
The first thing is to use the correct type of glue. I have found that cyanoacrylate (CA) glue works best. It is very strong and bonds quickly. Make sure that the surfaces to be glued are clean and dry, then apply a thin coat of glue to one surface and press the two surfaces together. Hold them in place for a few seconds until the glue sets up.
The next thing is to use the right type of covering material. I have found that Monokote or Solartex work well. They are both very strong and durable. Again, make sure that the surfaces to be covered are clean and dry, then cut a piece of covering material slightly larger than the surface to be covered. Apply a thin coat of glue to the surface and press the covering material in place. Hold it in place for a few seconds until the glue sets up.
The last thing is to trim the covering material.